Dodge refers to this part as a linear iacv solenoid (commonly known as idle air sontrol motor), it should be located on the firewall side of the throttlebody. The factory dodge part# you need is 4861552ac $83.20 available within a day or two.Where is the idle air control valve located on a 2004 Dodge Ram, 4.7l engine?
on the side of the throttlebody
Friday, February 12, 2010
Does a bad idle air control valve cause pour starting?
ya it can start rough and either die or run badDoes a bad idle air control valve cause pour starting?
Kind of. If it wasnt working the motor would immediatley die after intially starting. I.E. It wouldnt Idle.
Kind of. If it wasnt working the motor would immediatley die after intially starting. I.E. It wouldnt Idle.
Is the idle speed sensor the same as the idle air control valve on a 93 ford tempo?
Probably - although it's a misnomer.
The IAC or Idle Air Controller does the actual controlling of the idle speed while an idle speed sensor would indicate the actual idle speed input to the computer.Is the idle speed sensor the same as the idle air control valve on a 93 ford tempo?
no one is a sensor and the other is an actuater. idle speed sensor tells the computer how fast the engine is turning, and the computer tells the idle air control valve to open or close to correct idle speed.
The IAC or Idle Air Controller does the actual controlling of the idle speed while an idle speed sensor would indicate the actual idle speed input to the computer.Is the idle speed sensor the same as the idle air control valve on a 93 ford tempo?
no one is a sensor and the other is an actuater. idle speed sensor tells the computer how fast the engine is turning, and the computer tells the idle air control valve to open or close to correct idle speed.
I own a 1999 Ford F-150. My mechanic says I need to replace the Idle control air valve. What does this valve?
do and what does a defective one do to my idle speed and rpms? The motor is a 4.2 litre V6. Thanks, CurtI own a 1999 Ford F-150. My mechanic says I need to replace the Idle control air valve. What does this valve?
This is a computer controlled, electronic stepper motor that is used to control the idle speed. There is a target idle speed in the powertrain control module and it uses this motor to control the size of an orifice that bypasses air around the throttle plate. Increasing the amount of air (opening the valve), will increase the idle speed, while decreasing the amount of air (closing the valve), will decrease the idle speed. The PCM uses various sensor inputs to tell how fast the air is going, as well as to tell if the air/fuel mixture ratio is correct. A defective valve can have several symptoms. If it is stuck open, then it can cause a high idle or dying problem, if stuck closed it can cause low idle or for the vehicle to die. If it is slow to respond it can cause and idle hunting condition, like when it goes up and down. If it gets stuck in a certain position it can cause erratic idling. The valve also opens and closes, even when accelerating, decelerating and cruising to make the changes more smooth, and it can have performance affects even above idle.I own a 1999 Ford F-150. My mechanic says I need to replace the Idle control air valve. What does this valve?
The idle air motor does just that!It controls the idle. A bad one could cause stalling or erratic idle
The Idle Air Control valve (IAC) controls the engine idle speed. The output actuator is mounted on the throttle body and is controlled by voltage pulses sent from the PCM (computer). The IAC valve pintle moves in and out allowing more or less intake air into the system according to the engine conditions. To increase idle speed, the PCM retracts the IAC valve pintle away from the seat and allows more air to bypass the throttle bore. To decreaseidle speed, the PCM extends the IAC valve pintle towards the seat, reducing the air flow. To check the IAC valve unplug the electrical connector and, using an ohmmeter, measure the resistance across terinals A ans B, then terminals C and D. Each resistance check should indicate 40 to 80 ohms. A bad IAC will cause the engine to run rough, stall, hard to start. The engine can die when driving and make you mad enough to slap your moma. It can be dangerous to drive.
Check this link.....there is all the info you are asking for...AND MORE!!!
http://www.autoshop101.com/forms/h26.pdf
the idle control air valve main job/func you can noticed is when starting the engine in the morning.. did you noticed the idling of your car is a bit high? after 1-2minutes it all came to normal idling rev.. and when turning on the air-condition.. theres a slightly change in the RPMs.. why? its simple the idle control valve make sure your engine turn on.. rather than stepping on the gas pedal all the time
Its your air sensor for whats coming into the car, its something you can change yourself.
This is a common problem on Ford V8s.. The good news is that it is simple and cheap to replace. It is a small electric air control valve that is attached to your throttle body. It lets a regulated amount of air flow behind the closed butterfly when the throttle is closed so the truck can idle. When they get stuck you idle rough or the truck is hard to start or keep running at idle.. I think the part is about $60 US and you can just bolt on a new one in 15 minutes.. Hope this helps.
This is a computer controlled, electronic stepper motor that is used to control the idle speed. There is a target idle speed in the powertrain control module and it uses this motor to control the size of an orifice that bypasses air around the throttle plate. Increasing the amount of air (opening the valve), will increase the idle speed, while decreasing the amount of air (closing the valve), will decrease the idle speed. The PCM uses various sensor inputs to tell how fast the air is going, as well as to tell if the air/fuel mixture ratio is correct. A defective valve can have several symptoms. If it is stuck open, then it can cause a high idle or dying problem, if stuck closed it can cause low idle or for the vehicle to die. If it is slow to respond it can cause and idle hunting condition, like when it goes up and down. If it gets stuck in a certain position it can cause erratic idling. The valve also opens and closes, even when accelerating, decelerating and cruising to make the changes more smooth, and it can have performance affects even above idle.I own a 1999 Ford F-150. My mechanic says I need to replace the Idle control air valve. What does this valve?
The idle air motor does just that!It controls the idle. A bad one could cause stalling or erratic idle
The Idle Air Control valve (IAC) controls the engine idle speed. The output actuator is mounted on the throttle body and is controlled by voltage pulses sent from the PCM (computer). The IAC valve pintle moves in and out allowing more or less intake air into the system according to the engine conditions. To increase idle speed, the PCM retracts the IAC valve pintle away from the seat and allows more air to bypass the throttle bore. To decreaseidle speed, the PCM extends the IAC valve pintle towards the seat, reducing the air flow. To check the IAC valve unplug the electrical connector and, using an ohmmeter, measure the resistance across terinals A ans B, then terminals C and D. Each resistance check should indicate 40 to 80 ohms. A bad IAC will cause the engine to run rough, stall, hard to start. The engine can die when driving and make you mad enough to slap your moma. It can be dangerous to drive.
Check this link.....there is all the info you are asking for...AND MORE!!!
http://www.autoshop101.com/forms/h26.pdf
the idle control air valve main job/func you can noticed is when starting the engine in the morning.. did you noticed the idling of your car is a bit high? after 1-2minutes it all came to normal idling rev.. and when turning on the air-condition.. theres a slightly change in the RPMs.. why? its simple the idle control valve make sure your engine turn on.. rather than stepping on the gas pedal all the time
Its your air sensor for whats coming into the car, its something you can change yourself.
This is a common problem on Ford V8s.. The good news is that it is simple and cheap to replace. It is a small electric air control valve that is attached to your throttle body. It lets a regulated amount of air flow behind the closed butterfly when the throttle is closed so the truck can idle. When they get stuck you idle rough or the truck is hard to start or keep running at idle.. I think the part is about $60 US and you can just bolt on a new one in 15 minutes.. Hope this helps.
What is the difference between flow control and pressure reducing valve?
any difference in application of stem,fluid of these valvesWhat is the difference between flow control and pressure reducing valve?
None. The only difference is the controlled variable. All valves are flow control elements. The controller attached to the valve tells the valve what to do.
If it is a pressure control valve, the pressure sensor signal will be compared to a setpoint and move the valve to open or close. Same if it is a flow control valve, except that you will have a flow meter instead.
Addendum - Remember you cannot control the pressure in ';solid'; (liquid only systems).
.
.What is the difference between flow control and pressure reducing valve?
The difference is which process you are trying to control. A flow control valve is maintaining a desired setpoint of flow and a pressure control valve is maintaining a desired setpoint for pressure. Usually the best type of valve for controlling flow is a globe valve and it is used in all applications. Many types of valves are used for pressure control, but the most common is probably a gate valve.
Oh, and steam is a fluid
pressure and flow are two different things. a flow control valve controls the ammount of flow to a device i.e. steam turbine control valves. a pressure reducing valve reduces pressure to the user i.e. regulator on an airsystem used to drop instrument air to a useable pressure.
None. The only difference is the controlled variable. All valves are flow control elements. The controller attached to the valve tells the valve what to do.
If it is a pressure control valve, the pressure sensor signal will be compared to a setpoint and move the valve to open or close. Same if it is a flow control valve, except that you will have a flow meter instead.
Addendum - Remember you cannot control the pressure in ';solid'; (liquid only systems).
.
.What is the difference between flow control and pressure reducing valve?
The difference is which process you are trying to control. A flow control valve is maintaining a desired setpoint of flow and a pressure control valve is maintaining a desired setpoint for pressure. Usually the best type of valve for controlling flow is a globe valve and it is used in all applications. Many types of valves are used for pressure control, but the most common is probably a gate valve.
Oh, and steam is a fluid
pressure and flow are two different things. a flow control valve controls the ammount of flow to a device i.e. steam turbine control valves. a pressure reducing valve reduces pressure to the user i.e. regulator on an airsystem used to drop instrument air to a useable pressure.
What does idle air control valve do on a ford pickup?
my answer is try to check it out on auto repair shop..What does idle air control valve do on a ford pickup?
messes stuff up..lol
its supposed to control the emount of air it lets in while its idleing as i recall..but im a chevy guy and im an anti-computer in cars guy so ...i could be a bit biased also ;)What does idle air control valve do on a ford pickup?
it controls the right amount of air to the amount of gas its getting.one web hosting
messes stuff up..lol
its supposed to control the emount of air it lets in while its idleing as i recall..but im a chevy guy and im an anti-computer in cars guy so ...i could be a bit biased also ;)What does idle air control valve do on a ford pickup?
it controls the right amount of air to the amount of gas its getting.
Where is the HEATER CONTROL VALVE on a 1997 FORD EXPEDITION with a 4.6L engine?
Your truck doesn't have a heater control valve. It has heater hoses that run hot water straight into the heater core on the back of the engine on the passenger side. If your are having a problem getting heat inside the truck, but the gauge shows heating up ok, then you probably have a bad blend door or blend door actuator...Where is the HEATER CONTROL VALVE on a 1997 FORD EXPEDITION with a 4.6L engine?
there is not one there is a blend door motor that changes from cold to hot very common problem that it goes bad
there is not one there is a blend door motor that changes from cold to hot very common problem that it goes bad
How do you change the Pressure Control Solenoid Valve Assembly on a 2003 Impala 3.8L?
Remove the trans-axle side cover disconnect wire harness connector slide retaining clip off of PC. solenoid pull solenoid out of valve body. reverse procedure to reinstall
Can I use thermostat wire 18/5 for low voltage irrigation/sprinkler valve control??
Is there something cheaper to use than the rain bird wire that is 25$ for 100 feet??Can I use thermostat wire 18/5 for low voltage irrigation/sprinkler valve control??
that depends on whether you will be burying it..thermostat wire is not labeled as such ,and Will cause you trouble in the future.trust me you can pay less twice ,or pay right once .go with direct burial. 18 guage.multi strand. you will pay ten times as much when you hire an irrigation tech down the road to fix itCan I use thermostat wire 18/5 for low voltage irrigation/sprinkler valve control??
Yes, but depends on how far away the valves are from the controller.
You have voltage drop over distance and the larger wire carries the current with more ease. The solenoid will work but will fail quicker.
I repair alot of sprinklers where telephone and thermostat wire has been used. The thermostat wire doesn't seem to hold up as well, that is the insulation.
I always use multicondutor sprinkler wire or larger single wire for long distances but that is because I have to keep my reputation at a high level. I install and do maintenance on sprinkler systems for a living.
Yes, I use a 24 guage telephone wire for mine, it is the direct bury kind. With 5 conductor you can run 4 valves.
that depends on whether you will be burying it..thermostat wire is not labeled as such ,and Will cause you trouble in the future.trust me you can pay less twice ,or pay right once .go with direct burial. 18 guage.multi strand. you will pay ten times as much when you hire an irrigation tech down the road to fix itCan I use thermostat wire 18/5 for low voltage irrigation/sprinkler valve control??
Yes, but depends on how far away the valves are from the controller.
You have voltage drop over distance and the larger wire carries the current with more ease. The solenoid will work but will fail quicker.
I repair alot of sprinklers where telephone and thermostat wire has been used. The thermostat wire doesn't seem to hold up as well, that is the insulation.
I always use multicondutor sprinkler wire or larger single wire for long distances but that is because I have to keep my reputation at a high level. I install and do maintenance on sprinkler systems for a living.
Yes, I use a 24 guage telephone wire for mine, it is the direct bury kind. With 5 conductor you can run 4 valves.
Where is ford escort zetec air control valve?
I have a problem with uneven idle speed and engine stalling, ford diagnostic didn't show electical problem. I suspect it's something to do with the airflow or induction systemWhere is ford escort zetec air control valve?
its at the rear of the engine where the inlet manifold is, difficult to get at iac valve from above, you need to get at it from underneath and still not easiest one to remove, but when off wash the valve ports with carb cleaner, and refit, it might improve but if not my need new one, also worth checking is the pcv valve, and thats at front of engine on the right as you look at engine, you will see small rubber pipe that pushes in to a small valve, they play up sometimes, to check if its faulty, clamp off the pipe and note idle speed and smoothness. if it gets better , that could be your problem, good luck,
ford mechanic
ianWhere is ford escort zetec air control valve?
it will be on the throttle body
Ask a main dealer. Good luck
its at the rear of the engine where the inlet manifold is, difficult to get at iac valve from above, you need to get at it from underneath and still not easiest one to remove, but when off wash the valve ports with carb cleaner, and refit, it might improve but if not my need new one, also worth checking is the pcv valve, and thats at front of engine on the right as you look at engine, you will see small rubber pipe that pushes in to a small valve, they play up sometimes, to check if its faulty, clamp off the pipe and note idle speed and smoothness. if it gets better , that could be your problem, good luck,
ford mechanic
ianWhere is ford escort zetec air control valve?
it will be on the throttle body
Ask a main dealer. Good luck
How do you replace idle control valve on 86 bmw 528e?
First check the vacuum hoses for leaks.
The idle control valve is beside the intake manifold.U can replace yourself,but can u adjust it.?
To make it easier,just go to a qualified mechanic and get it changed and adjusted within minutes.How do you replace idle control valve on 86 bmw 528e?
One end is in intake boot, the other end is a cable connector, and the center is wrapped around the mounting bracket. Steps are:
1) you remove electric connector
2) pry on bottom of the mounting bracket to open the mounting point
3) slide the valve out of the intake
installation is reverse. You can sometimes clean this with carb cleaner to get it running again. I had to replace mine, and it wasn't a cheap part. (I think I paid around $100, made by Bosch)
The idle control valve is beside the intake manifold.U can replace yourself,but can u adjust it.?
To make it easier,just go to a qualified mechanic and get it changed and adjusted within minutes.How do you replace idle control valve on 86 bmw 528e?
One end is in intake boot, the other end is a cable connector, and the center is wrapped around the mounting bracket. Steps are:
1) you remove electric connector
2) pry on bottom of the mounting bracket to open the mounting point
3) slide the valve out of the intake
installation is reverse. You can sometimes clean this with carb cleaner to get it running again. I had to replace mine, and it wasn't a cheap part. (I think I paid around $100, made by Bosch)
Suzuki x90 what does idle control valve look like and where can I find it?
Descriptions %26amp; pictures of engine management parts;
http://www.kick-fix.com/sensors/testing-鈥?/a>
The IAC valve is in the inlet manifold.one web hosting
http://www.kick-fix.com/sensors/testing-鈥?/a>
The IAC valve is in the inlet manifold.
What is the purpose of idle air control valve on an automobile?..?
yep, what Tim said. Because when the engine is not at idle the throttle plate is what is controlling the engine rpm. If the throttle is closed you need to regulate the amount of air going into the engine in order to regulate the rpm.What is the purpose of idle air control valve on an automobile?..?
An electrically-operated valve which allows air to bypass the throttle plate in a fuel injected engine to regulate engine idle speed. Basically it keeps the idle set just right.
An electrically-operated valve which allows air to bypass the throttle plate in a fuel injected engine to regulate engine idle speed. Basically it keeps the idle set just right.
Where is the idle air control valve in an 2001 Ford Mustang 3.8L v6?
It should be on or very near the throttle body.Where is the idle air control valve in an 2001 Ford Mustang 3.8L v6?
bolted to the upper intake manifold near the throttle body. round cylinder with an electrical plug, 2 wire held in by 2 8mm bolts. if you can't find it by idle air control, its also known as idle air bypass. are you trying to gid rid of a galloping idle?Where is the idle air control valve in an 2001 Ford Mustang 3.8L v6?
on the trottle body assembly
should be exactly where Gemini stated.
bolted to the upper intake manifold near the throttle body. round cylinder with an electrical plug, 2 wire held in by 2 8mm bolts. if you can't find it by idle air control, its also known as idle air bypass. are you trying to gid rid of a galloping idle?Where is the idle air control valve in an 2001 Ford Mustang 3.8L v6?
on the trottle body assembly
should be exactly where Gemini stated.
How to test out a bad idle air control valve?
on a 2002 ford mustang gt, auto.How to test out a bad idle air control valve?
Turn the car off and unplug the IAC. Restart the engine. If it runs fast, then it's probably O.K. If there is no change, it's probably bad.
I would also take the IAC off the engine and inspect it for varnish and carbon deposits. You might get lucky and be able to clean it up with carb spray.How to test out a bad idle air control valve?
Unplug the electrical connector on the valve. If the problem doesn't change then most likely it is the valve If the problem gets worse than the valve is prob OK. Fords are know for IAC problems. Anything from rangers to mustangs.
just clean it
Turn the car off and unplug the IAC. Restart the engine. If it runs fast, then it's probably O.K. If there is no change, it's probably bad.
I would also take the IAC off the engine and inspect it for varnish and carbon deposits. You might get lucky and be able to clean it up with carb spray.How to test out a bad idle air control valve?
Unplug the electrical connector on the valve. If the problem doesn't change then most likely it is the valve If the problem gets worse than the valve is prob OK. Fords are know for IAC problems. Anything from rangers to mustangs.
just clean it
Where is the heater control valve?
i am trying to change the heater control valve in a 2000 ford taurus but not sure where is located and look for almost 2 days still don't know yet can anybody tell me please?Where is the heater control valve?
Follow the heater outlet hose to where it attaches to the motor; the valve should be the (if you can see it in the maze of all the stuff in there !!)
Follow the heater outlet hose to where it attaches to the motor; the valve should be the (if you can see it in the maze of all the stuff in there !!)
Where is the heater control valve on a 1996 ford Taurus.?
I have to assume you are talking about the temperature actuator, also referred to as an air blend actuator. It controls the change in the A/C system from hot to cold. The part was bad to begin with thanks to the subcontractor Ford buys them from. They cost about $60 and can be changed in about an hour if you have at least some moderate mechanical expertise.
The air box is in the center of the underside of the dash, near the top, so it is a bit of a reach in a Taurus. I've changed one in a Windstar, so I had a little more physical wiggle room than you'll get under the dash of the Taurus.
The air box is in the center of the underside of the dash, near the top, so it is a bit of a reach in a Taurus. I've changed one in a Windstar, so I had a little more physical wiggle room than you'll get under the dash of the Taurus.
Where is the heater control valve on a 1996 ford Taurus.?
I have to assume you are talking about the temperature actuator, also referred to as an air blend actuator. It controls the change in the A/C system from hot to cold. The part was bad to begin with thanks to the subcontractor Ford buys them from. They cost about $60 and can be changed in about an hour if you have at least some moderate mechanical expertise.
The air box is in the center of the underside of the dash, near the top, so it is a bit of a reach in a Taurus. I've changed one in a Windstar, so I had a little more physical wiggle room than you'll get under the dash of the Taurus.one web hosting
The air box is in the center of the underside of the dash, near the top, so it is a bit of a reach in a Taurus. I've changed one in a Windstar, so I had a little more physical wiggle room than you'll get under the dash of the Taurus.
What do i need to fix on the EGR air control valve?
the engine still revse up highWhat do i need to fix on the EGR air control valve?
High revs on an engine would have nothing to do with the EGR valve....do you mean the Idle air control valve? I bet you do.... :)
The IAC might simply be dirty and need to be cleaned off. A good throttle/carb cleaner will do that. If cleaning it doesn't solve the high rev problem, it might need to be replaced (assuming the IAC is really the cause to start with).What do i need to fix on the EGR air control valve?
EGR valves do not make the engine rev up,you have an air leak somewhere on your intake manifold after the throttle plate. (EGR stands for exhaust gas reciculation ) if exhaust gas was going into the engine at idle the engine would idle roughly or stall.EGR valves only work above idle speeds.
The EGR valve IS vacuum controlled to open on some cars - so if the diagphram is burst it will be like a vacuum leak and may make your engine rev high. First check vacuum hoses to the EGR valve - thsi is a cheap fix - under a few dollars. The valve itself is not too sopjhisitcated but is pricey - for example on a cadillac deville its $150 - BUT it is very easy to replace. if you are sure its the valve check prices at www.rockauto.com and autozone.com - there are probably two bolts holding it down - on us cars 9/16 or 1/2 inch. You will need a crawfoot socket or an angled wrench (like a timing wrench) to get the bolts under the egr usually because your wrench or socket cant get on it - so but one for $9 and make life easy.
you can replace it
or you can try to clean it
Professionally, take it to a mechanic.
the egr is an Exhaust Gas Recircultion valve. i woul have the computer read first if it is the egr just replace it
Its a fuel economy thing
High revs on an engine would have nothing to do with the EGR valve....do you mean the Idle air control valve? I bet you do.... :)
The IAC might simply be dirty and need to be cleaned off. A good throttle/carb cleaner will do that. If cleaning it doesn't solve the high rev problem, it might need to be replaced (assuming the IAC is really the cause to start with).What do i need to fix on the EGR air control valve?
EGR valves do not make the engine rev up,you have an air leak somewhere on your intake manifold after the throttle plate. (EGR stands for exhaust gas reciculation ) if exhaust gas was going into the engine at idle the engine would idle roughly or stall.EGR valves only work above idle speeds.
The EGR valve IS vacuum controlled to open on some cars - so if the diagphram is burst it will be like a vacuum leak and may make your engine rev high. First check vacuum hoses to the EGR valve - thsi is a cheap fix - under a few dollars. The valve itself is not too sopjhisitcated but is pricey - for example on a cadillac deville its $150 - BUT it is very easy to replace. if you are sure its the valve check prices at www.rockauto.com and autozone.com - there are probably two bolts holding it down - on us cars 9/16 or 1/2 inch. You will need a crawfoot socket or an angled wrench (like a timing wrench) to get the bolts under the egr usually because your wrench or socket cant get on it - so but one for $9 and make life easy.
you can replace it
or you can try to clean it
Professionally, take it to a mechanic.
the egr is an Exhaust Gas Recircultion valve. i woul have the computer read first if it is the egr just replace it
Its a fuel economy thing
Whats a fuel evaporation control valve?
ok my check engine light turned on and so i took my bmw to get it diagnosed and it turns out its this fuel evaporation purge control valve? can someone explain this to me in plain simple english? thanx in advanceWhats a fuel evaporation control valve?
A small solenoid that allows gas vapors to be purged from the charcoal canister in to the engine. If you want simpler, It's busted, get it fixed.Whats a fuel evaporation control valve?
All cars have a canister on a hose attached to the gas tank to capture the fumes as the gas sloshes around. This canister is purged every once in a while and that is what the valve controls. It's an emissions issue. It might cause a pressure test fail if you have to get it smog tested depending if the valve is stuck open of closed. Drive on
A small solenoid that allows gas vapors to be purged from the charcoal canister in to the engine. If you want simpler, It's busted, get it fixed.Whats a fuel evaporation control valve?
All cars have a canister on a hose attached to the gas tank to capture the fumes as the gas sloshes around. This canister is purged every once in a while and that is what the valve controls. It's an emissions issue. It might cause a pressure test fail if you have to get it smog tested depending if the valve is stuck open of closed. Drive on
Where is Idle Air Control Valve located on a 88 Firebird?
It should be on the back left corner of the throttle body. I think its 3 wires coming outWhere is Idle Air Control Valve located on a 88 Firebird?
if it is tbi,and it is a v8 motor, it is located on the left back corner of the throttle body..
if it is tbi,and it is a v8 motor, it is located on the left back corner of the throttle body..
How do i clean the idle air control valve on my 97 lexus es300?
for a little while now 1 out of 5 times i start my car, the idle will go up then drop and the car will shut off. when i give it gas it catches and idles normally, but i dont want this problem to persist. i read on some forums that it is the idle air control valve. is this the problem? if so how do i clean it? if you are okay with it, leave an email so i can email you directly with any more questions. thanksHow do i clean the idle air control valve on my 97 lexus es300?
To clean this valve, it's a pain in the ****. Most dealerships will just replace it. Here's what I recommend.
Remove the control valve from your manifold just below the air cleaner on the fuel injection air feed tube. soak it in chem tool for about an hour. Let it dry out for about four to six hours. Reinstall.How do i clean the idle air control valve on my 97 lexus es300?
It's either the IAC or the TPS(throttle position sensor). Try cleaning it with Brakleen.
To clean this valve, it's a pain in the ****. Most dealerships will just replace it. Here's what I recommend.
Remove the control valve from your manifold just below the air cleaner on the fuel injection air feed tube. soak it in chem tool for about an hour. Let it dry out for about four to six hours. Reinstall.How do i clean the idle air control valve on my 97 lexus es300?
It's either the IAC or the TPS(throttle position sensor). Try cleaning it with Brakleen.
96 dx honda civic idle air control valve?
Where is your idle air control valve located on at?96 dx honda civic idle air control valve?
it is located on the back side of the intake plenum, between the plenum and the firewall. its bolted to the plenum with two 10mm bolts and has two small vacuum lines coming off the bottom side of it. hope this helps
it is located on the back side of the intake plenum, between the plenum and the firewall. its bolted to the plenum with two 10mm bolts and has two small vacuum lines coming off the bottom side of it. hope this helps
Location of heater control valve?
where is the location of the heater control valve in a 2001 cadillac catera? is it easy to DIY?Location of heater control valve?
its not too bad to get too,it should be in plain site right out side the heater box,where the hoses go through ,on those they ran pretty close to the firewall,but still easy to get too,if you don't see it there,then they put it on the inside of the heater box,on some they did,they sort of did a split year thing on some of them and tried it both ways,seems like the ones that were enclosed gave more problems than the ones you could get to real easy,i hope yours is on the outside,good luck with it.one web hosting
its not too bad to get too,it should be in plain site right out side the heater box,where the hoses go through ,on those they ran pretty close to the firewall,but still easy to get too,if you don't see it there,then they put it on the inside of the heater box,on some they did,they sort of did a split year thing on some of them and tried it both ways,seems like the ones that were enclosed gave more problems than the ones you could get to real easy,i hope yours is on the outside,good luck with it.
When my car is idling it stalls. could this be the idle air control valve acting up?
It's a possibility if it runs ok otherwise. Also could be a vacuum leak at brake booster and it could be the throttle position sensor. The iac sometimes sticks.When my car is idling it stalls. could this be the idle air control valve acting up?
could be...or fuel pressure regulator or fuel filter..just a few things to consider...have a mechanic take a look at itWhen my car is idling it stalls. could this be the idle air control valve acting up?
MOST likely but if you really dont know about auto or dont know how to test the IAC then you should probably take it to a shop and get it diagnosed then you can do the repair if its simple
I'm an automotive mechanic... more than likely, it is NOT the IAC valve. When you put a load on it (put it into reverse, drive) does it become worse? Check the connections to your MAF (Mass Air Flow) sensor. Or you could be misfiring. I wouldn't know exactly, because I do not know what kind of car you have. However, take it to a garage and ask them to run a diagnostics check on your vehicle. If the check engine light is on, this is mandatory. Good luck!
Yes, it could be. If the idle air control is not working, then it will not properly allow air flow on idle, causing low and rough idle.
could be...or fuel pressure regulator or fuel filter..just a few things to consider...have a mechanic take a look at itWhen my car is idling it stalls. could this be the idle air control valve acting up?
MOST likely but if you really dont know about auto or dont know how to test the IAC then you should probably take it to a shop and get it diagnosed then you can do the repair if its simple
I'm an automotive mechanic... more than likely, it is NOT the IAC valve. When you put a load on it (put it into reverse, drive) does it become worse? Check the connections to your MAF (Mass Air Flow) sensor. Or you could be misfiring. I wouldn't know exactly, because I do not know what kind of car you have. However, take it to a garage and ask them to run a diagnostics check on your vehicle. If the check engine light is on, this is mandatory. Good luck!
Yes, it could be. If the idle air control is not working, then it will not properly allow air flow on idle, causing low and rough idle.
In which web i can see about direction control valve used in hydraulic system?
it used for automatic functionIn which web i can see about direction control valve used in hydraulic system?
Huh?
Huh?
Does the VVT(Variable Valve Timing) control the air volume in the engine?
and how the VVT works and whether it icreases or decreases the volume of the air admitted to the engineDoes the VVT(Variable Valve Timing) control the air volume in the engine?
the intake valves allow AIR into the engines combustion chamber
vvt at higher engine speeds allows the INTAKE valve to stay open longer to allow more air and helps to combust more fuel
vvt at higher speed allows the EXHAUST valve to stay open longer to allow more exhaust to exit quicker
the intake valves allow AIR into the engines combustion chamber
vvt at higher engine speeds allows the INTAKE valve to stay open longer to allow more air and helps to combust more fuel
vvt at higher speed allows the EXHAUST valve to stay open longer to allow more exhaust to exit quicker
How do i clean the idle air control valve for a '94 honda prelude?
clean all the dirt off of it use some sort of sensor cleaner at your auto store than take a towel and wipe it downHow do i clean the idle air control valve for a '94 honda prelude?
spray some carb cleaner where the screen is.
let it drain out and COMPLETELY dry (maybe 3-4 hours)
then u should be good to go
spray some carb cleaner where the screen is.
let it drain out and COMPLETELY dry (maybe 3-4 hours)
then u should be good to go
Slipstream, where is the Vent door and control valve?
i'm pretty sure both hoses to and from the radiator were warm... if the hose from the thermostat is cold what should I do? because I know the top hose gets very warm... where can I find the vent door and control valve.... we have this mitsubishi, and everything on the inside falls off like the vent covers, and the radio face... seems like they don't snap in, and aren't stuck together very well....Slipstream, where is the Vent door and control valve?
the vent door is located near the heater core......it,s job is to mix fresh air with heated/cooled air according to your demand,s....follow from temperature selector at heater switch to vent door....it,s usually vacuum controled...but sometimes it,s electric...........................your heater control valve is located under the hood ...close to the fire wall ....in one of the heater hoses....it also is usually vacuum controled.......but not all car,s have them..........if the hoses at the thermostat aren't hot enough ..this may be due to external cold temperature....but if their cold you either have an air lock.. or a bad thermostat.
the vent door is located near the heater core......it,s job is to mix fresh air with heated/cooled air according to your demand,s....follow from temperature selector at heater switch to vent door....it,s usually vacuum controled...but sometimes it,s electric...........................your heater control valve is located under the hood ...close to the fire wall ....in one of the heater hoses....it also is usually vacuum controled.......but not all car,s have them..........if the hoses at the thermostat aren't hot enough ..this may be due to external cold temperature....but if their cold you either have an air lock.. or a bad thermostat.
Where is the dodge idle air control valve?
what is this an how do i tell if its cloged? on a 5.2 v-8 magnumWhere is the dodge idle air control valve?
I am going to assume that you are having issues with the vehicle stalling probably when comming to a stop. There is no valve for idle control it is actually a solenoid. It is located on the drivers side of the throttle body, it is round and is held on by two screws. The first thing to try is to get some air intake cleaner, open the throttle plate, spray it down and clean with an old tooth brush. You will likely find alot of black soot in the throttle plate. Hope this helpsone web hosting
I am going to assume that you are having issues with the vehicle stalling probably when comming to a stop. There is no valve for idle control it is actually a solenoid. It is located on the drivers side of the throttle body, it is round and is held on by two screws. The first thing to try is to get some air intake cleaner, open the throttle plate, spray it down and clean with an old tooth brush. You will likely find alot of black soot in the throttle plate. Hope this helps
Can all the types of valves(Ball, Gate, Globe, etc) also fall under control valve classification?
I still get a little confused classifying valves, Control valves, Block valves, Double block and bleed, etc.Can all the types of valves(Ball, Gate, Globe, etc) also fall under control valve classification?
Yes - and no - certain types of valves, such as globe and needle valves are more suitable for control than others, such as ball valves. A ball valve will achieve 90% flow at approximately 10% open. It doesn't give you a lot of room for control. A globe valve, on the other hand, has a much more linear ';open vs. flow'; response.
If your control, however, is purely ';ON/OFF'; then a ball valve is perfectly suitable.
Of course, in actual practive, if there is any way possible to mis-apply a valve, somebody has probably done it.Can all the types of valves(Ball, Gate, Globe, etc) also fall under control valve classification?
The answer above is very good but there are certain ball valves made for control and they have a opening shape that gives them a specific flow to opening ratio that permits them to be used for control
Yes - and no - certain types of valves, such as globe and needle valves are more suitable for control than others, such as ball valves. A ball valve will achieve 90% flow at approximately 10% open. It doesn't give you a lot of room for control. A globe valve, on the other hand, has a much more linear ';open vs. flow'; response.
If your control, however, is purely ';ON/OFF'; then a ball valve is perfectly suitable.
Of course, in actual practive, if there is any way possible to mis-apply a valve, somebody has probably done it.Can all the types of valves(Ball, Gate, Globe, etc) also fall under control valve classification?
The answer above is very good but there are certain ball valves made for control and they have a opening shape that gives them a specific flow to opening ratio that permits them to be used for control
For which application globe control valve is use and butter fly control valve use?
in process we r using various type of control valve , i want to know about which control valve more sutiable for fluid, steam, gas, solidFor which application globe control valve is use and butter fly control valve use?
A globe valve has a better flow characteristic. That is the flow tends to be more proportional to percent open. There are several different versions of the globe type control valves with different variations from a pure lineal version. This means you can get a better response from the valves to meet the systems flow requirements.
A butterfly valve is best as an open/close control valve but they can also be used for proportional control but not with the same degree of precise response as a globe valve.
Butterfly valves also tend to be used in very large lines where a globe type control valve is not manufactured or is too expensive. A third type of valve is available for large flow rates that is neither a globe or butterfly. It is a V-Ball valve.
With regard to the fluid being handled, the material of construction for the seat and globe will usually vary rather than the type of valve.
The science and art of designing and selecting control valves is really too complex to be answered here. Some of the control valve manufacturers have information on control valve selection that might be helpful. You might try contacting someone like Fisher Controls.For which application globe control valve is use and butter fly control valve use?
I will rstrict myself to only the types other wise the selection criteria are many.
GLOBE: These are used for controlling a process parameter loop. They cause medium pr. drop %26amp; are ideal for clean fluids. The shape of the stem is contoured to get the desired characteristics. The repeatability of the type in flow control make it ideal for closed loop control.
BUTTERFLY: These are low pr drop devise that are used primarily where u can't allow higher pressure drops. Good for clean fluids in on/off service. Even allowed for gases. it opens/shuts faster than other types of valves. Sealing characteristics are not as good as ball valve, particularly unsuitable for fluids containing solids.
A globe valve has a better flow characteristic. That is the flow tends to be more proportional to percent open. There are several different versions of the globe type control valves with different variations from a pure lineal version. This means you can get a better response from the valves to meet the systems flow requirements.
A butterfly valve is best as an open/close control valve but they can also be used for proportional control but not with the same degree of precise response as a globe valve.
Butterfly valves also tend to be used in very large lines where a globe type control valve is not manufactured or is too expensive. A third type of valve is available for large flow rates that is neither a globe or butterfly. It is a V-Ball valve.
With regard to the fluid being handled, the material of construction for the seat and globe will usually vary rather than the type of valve.
The science and art of designing and selecting control valves is really too complex to be answered here. Some of the control valve manufacturers have information on control valve selection that might be helpful. You might try contacting someone like Fisher Controls.For which application globe control valve is use and butter fly control valve use?
I will rstrict myself to only the types other wise the selection criteria are many.
GLOBE: These are used for controlling a process parameter loop. They cause medium pr. drop %26amp; are ideal for clean fluids. The shape of the stem is contoured to get the desired characteristics. The repeatability of the type in flow control make it ideal for closed loop control.
BUTTERFLY: These are low pr drop devise that are used primarily where u can't allow higher pressure drops. Good for clean fluids in on/off service. Even allowed for gases. it opens/shuts faster than other types of valves. Sealing characteristics are not as good as ball valve, particularly unsuitable for fluids containing solids.
1995 camaro flow control valve location?
my heater wont work and i suspect the flow control valve or the heater core. please help me locate the flow control valve. 1995 3.4L v6 camaro.1995 camaro flow control valve location?
they are located on the right side of the engine compartment you will notice two hoses running back to the inside of the firewall it will be located on these if it has not already been removed. most of the time when a camaro heat/ac system does not work it is a faulty blend door actuator located under the dash, it will not allow the system to switch the blend door from cold to hot good luck
they are located on the right side of the engine compartment you will notice two hoses running back to the inside of the firewall it will be located on these if it has not already been removed. most of the time when a camaro heat/ac system does not work it is a faulty blend door actuator located under the dash, it will not allow the system to switch the blend door from cold to hot good luck
Where Is the Idle Air Control Valve on a 2004 F150 5.4L 3V V8...any help would be greatly appreciated?
2004 F150 V8 5.4L 3VWhere Is the Idle Air Control Valve on a 2004 F150 5.4L 3V V8...any help would be greatly appreciated?
This particular vehicle does not have an IAC valve. This is because it is equipped with ETC (Electronic Throttle Control). This means there is no mechanical connection between the accelerator pedal and the throttle plate. Instead, the throttle plate is controlled by an electric motor to control its engine speed, based on ';input'; it receives from the PCM. The accelerator pedal is connected to three poteniometers. Two that increase, and one that decreases voltage in a particular proportion. If they fail, the vehicle goes into what's called a ';forced idle'; mode of operation. Hope this helps.Where Is the Idle Air Control Valve on a 2004 F150 5.4L 3V V8...any help would be greatly appreciated?
on the throttle body
This particular vehicle does not have an IAC valve. This is because it is equipped with ETC (Electronic Throttle Control). This means there is no mechanical connection between the accelerator pedal and the throttle plate. Instead, the throttle plate is controlled by an electric motor to control its engine speed, based on ';input'; it receives from the PCM. The accelerator pedal is connected to three poteniometers. Two that increase, and one that decreases voltage in a particular proportion. If they fail, the vehicle goes into what's called a ';forced idle'; mode of operation. Hope this helps.Where Is the Idle Air Control Valve on a 2004 F150 5.4L 3V V8...any help would be greatly appreciated?
on the throttle body
I need a control valve for a cat 539 loader.?
I am looking for a parting out cat 539 knuckle boom loader. I need a control valve for mine.I need a control valve for a cat 539 loader.?
call your local implement repair shop,Im sure they will find one or rebuild yours.
call your local implement repair shop,Im sure they will find one or rebuild yours.
My opel corsa car broke down and i was told its idle speed control valve, why did this happen & is it serious?
Does anyone know if its expensive to get fixed and would it be the way i drove the car to make this happenMy opel corsa car broke down and i was told its idle speed control valve, why did this happen %26amp; is it serious?
it will cost you 拢5 from a breakers yard...and no,lol,its not they way uyou drive.My opel corsa car broke down and i was told its idle speed control valve, why did this happen %26amp; is it serious?
you say your car broke down. is your car cutting out when comming too a stop this would be an idle valve but the car would start and run again . as iv seen a lot of these replaced because the computer has told them this is the problem when it was infact the mass air flow meter was faulty or timming chain jumped who told you its the i.c.v and whats happening with your car also what age is it and what engine is it. and in answer too your question no it wouldnt have been because of your driving just part of the joy of motoring
new mass air flow meters are 拢70 their easy too check unplug it and start car up if it runs better than when its plugged in then its the m.a.f sensor
cost you around 拢90, a second hand one is fine if you can guarantee it works.
common fault on these and nothing to do with how you drive the car.one web hosting
it will cost you 拢5 from a breakers yard...and no,lol,its not they way uyou drive.My opel corsa car broke down and i was told its idle speed control valve, why did this happen %26amp; is it serious?
you say your car broke down. is your car cutting out when comming too a stop this would be an idle valve but the car would start and run again . as iv seen a lot of these replaced because the computer has told them this is the problem when it was infact the mass air flow meter was faulty or timming chain jumped who told you its the i.c.v and whats happening with your car also what age is it and what engine is it. and in answer too your question no it wouldnt have been because of your driving just part of the joy of motoring
new mass air flow meters are 拢70 their easy too check unplug it and start car up if it runs better than when its plugged in then its the m.a.f sensor
cost you around 拢90, a second hand one is fine if you can guarantee it works.
common fault on these and nothing to do with how you drive the car.
Where is the ';Air control valve'; on a MK 3 VW Golf (petrol engine)?
It is a 2.0 litre 8v engine model (115bhp)Where is the ';Air control valve'; on a MK 3 VW Golf (petrol engine)?
It's this bit;
http://www.autopartswarehouse.com/mmp/vw鈥?/a>
should be connected to the inlet manifold %26amp; ducting.
It's this bit;
http://www.autopartswarehouse.com/mmp/vw鈥?/a>
should be connected to the inlet manifold %26amp; ducting.
I have a toilet that has a shut off valve with no knob. How can I control water flow?
why are you trying to control the flow to your toilet?I have a toilet that has a shut off valve with no knob. How can I control water flow?
by another knob, cheap at lowes or home depotI have a toilet that has a shut off valve with no knob. How can I control water flow?
1 - Use pliers or vise grips on the valve stem.
2 - Replace it.
Maybe one of the newer type that you push in or pull out. They are made of plastic and I personally do not like them Replace it with one that has a faucet handle it makes things a whole lot better.
by another knob, cheap at lowes or home depotI have a toilet that has a shut off valve with no knob. How can I control water flow?
1 - Use pliers or vise grips on the valve stem.
2 - Replace it.
Maybe one of the newer type that you push in or pull out. They are made of plastic and I personally do not like them Replace it with one that has a faucet handle it makes things a whole lot better.
Location of Heater control valve 99 ford taurus?
where is the location of the heater control valve and adivce on how to replace?Location of Heater control valve 99 ford taurus?
its not a valve ,its an electric motor under the radio.....the gears are probably stripped ....common problem
its not a valve ,its an electric motor under the radio.....the gears are probably stripped ....common problem
Honda idle air control valve problem?
95 Honda Del Sol with the D15 1.5 lit engine. On cold start, it will start up with really low idle (almost to a point of stalling) for about 4 to 8 seconds, then the idle will shoot up to normal warm up idle. If I just turn the engine off right the away and restart, it will restart up with the normal warm up idle.
Could this be a bad idle air controller problem or something else?
Thanks!Honda idle air control valve problem?
it can be a bad IAC motor or it might just need throttle body cleaning
Could this be a bad idle air controller problem or something else?
Thanks!Honda idle air control valve problem?
it can be a bad IAC motor or it might just need throttle body cleaning
What are the symptoms of a bad Idle Air Control Valve?
stalls for no reason....whistle noise from engine..erratic idle..starts and stalls.....check engine light comes on.....could be any combination of these or just one....carbon keeping the prindle from sealing...(the iac is still working,but it cant seal because of this...lots of good iacs replaced because of this condition)...What are the symptoms of a bad Idle Air Control Valve?
the smell of gas everytime you turn the on. whistley noise coming out of the air.What are the symptoms of a bad Idle Air Control Valve?
idles too fast..or wont idle at all...depends wether electrical r temp fault really
the smell of gas everytime you turn the on. whistley noise coming out of the air.What are the symptoms of a bad Idle Air Control Valve?
idles too fast..or wont idle at all...depends wether electrical r temp fault really
96 chevy cavalier heater control valve?
Where is the illusive heater control valve?96 chevy cavalier heater control valve?
The only ';valve'; i could think you are referring too would be the vacuum control on the back of the dash mounted heater controls. They do not have a valve in the coolant lines. The heat turned on or off by a vacuum operated door inside the heater box that merely closes and blocks the heat from escaping into the car. If you are having heater problems first make sure both lines running to the firewall feel hot/warm when engine is at temperature. Secondly you will have to find the actuators under dash on the heater box and make sure they are moving if not ck for vacuum.......one web hosting
The only ';valve'; i could think you are referring too would be the vacuum control on the back of the dash mounted heater controls. They do not have a valve in the coolant lines. The heat turned on or off by a vacuum operated door inside the heater box that merely closes and blocks the heat from escaping into the car. If you are having heater problems first make sure both lines running to the firewall feel hot/warm when engine is at temperature. Secondly you will have to find the actuators under dash on the heater box and make sure they are moving if not ck for vacuum.......
How do I control (on/off) an electronic valve/solenoid from a mile away/?
I am building a private unmanned aerial vehicle and I need to figure out what i need to operate an on/off solenoid valve from a far distance. As of right now, testing will begin around a 1 mile range. I am a mechanical engineer and my electronic knowledge is not extensive. thanks for any help in advance.How do I control (on/off) an electronic valve/solenoid from a mile away/?
I don't know what your budget is. You could use a RC radio control and the switching circuits, perhaps.
Otherwise, a small low powered transmitter and receiver with a DTMF encoder / decoder (to avoid spurious triggering).How do I control (on/off) an electronic valve/solenoid from a mile away/?
Take a feed out of a mobile phone.
I don't know what your budget is. You could use a RC radio control and the switching circuits, perhaps.
Otherwise, a small low powered transmitter and receiver with a DTMF encoder / decoder (to avoid spurious triggering).How do I control (on/off) an electronic valve/solenoid from a mile away/?
Take a feed out of a mobile phone.
I have changed my idle control valve for my peugeot 406(petrol) and my car rev still goes up and down.?
My car's rev is up and down when my car comes to an idle position or stops. Even the mechanic don't seem to know the solution.I have changed my idle control valve for my peugeot 406(petrol) and my car rev still goes up and down.?
check for a vacuum pipe off sucking in air...also ask the mechanic if its a multiplex 406...the BSI unit may need reset....it may be as simply as disconnecting your battery for 3 mins,reconnect and switch on lights...this resets the BSI....then drive it for 15 mins till the ecu relearns you driving technicsI have changed my idle control valve for my peugeot 406(petrol) and my car rev still goes up and down.?
Read this info:
Peugeot Common ECU Failures
PEUGEOT 306 1.4 / 1.8(16V) and 406 1.8(16V) MODELS FROM 1997 to 2002 - IDLE CONTROL PROBLEMS. SAGEM SL96 (3 row, 55 pin) ECU suffers from damage to idle control CAUSED BY DEFECTIVE COILS. Replacing ECU WITHOUT REPLACING COILS WILL RESULT IN NEW ECU FAILING WITHIN VERY SHORT TIME FRAME.
Sagem SL96 Symptoms
1) Car suffers idle control problems manifested as rough running at idle and stalling at traffic lights.
2) Check engine light usually illuminates with coil pack fail and idle control fault codes.
Diagnostic Checklist
1) Check fault codes - if fault code does not identify which coil has failed, REPLACE BOTH. Coil failure almost guarantees ECU failure but run car with new coil(s) - if idle control is correct - and idle control fault code does not reappear then ECU has probably survived.
Your coil packs will need to be replaced, if your lucky the ecu wont have been damaged.
Check for blocked pipes from the idle valve air intakes and also check the wiring on the idle valve, and spray some carb cleaner into the idle valve and let it soak in for about 30 mins. Then try it again. Also make sure there are no air leaks where the idle valve is fitted. It could also be a air flow meter problem.
it does sound like you have a problem on the air induction side of things, has the mechanic had a very thorough look at all the vacuum pipes and even the inlet manifold gasket, some times all that is needed is a good clean out of the air idle Control valve. Good luck.
A engine that wont idle properly sounds more like a blockage in the fuel system
what year is the car?
if it has an ecu the problem could be with one of the sensors
check for a vacuum pipe off sucking in air...also ask the mechanic if its a multiplex 406...the BSI unit may need reset....it may be as simply as disconnecting your battery for 3 mins,reconnect and switch on lights...this resets the BSI....then drive it for 15 mins till the ecu relearns you driving technicsI have changed my idle control valve for my peugeot 406(petrol) and my car rev still goes up and down.?
Read this info:
Peugeot Common ECU Failures
PEUGEOT 306 1.4 / 1.8(16V) and 406 1.8(16V) MODELS FROM 1997 to 2002 - IDLE CONTROL PROBLEMS. SAGEM SL96 (3 row, 55 pin) ECU suffers from damage to idle control CAUSED BY DEFECTIVE COILS. Replacing ECU WITHOUT REPLACING COILS WILL RESULT IN NEW ECU FAILING WITHIN VERY SHORT TIME FRAME.
Sagem SL96 Symptoms
1) Car suffers idle control problems manifested as rough running at idle and stalling at traffic lights.
2) Check engine light usually illuminates with coil pack fail and idle control fault codes.
Diagnostic Checklist
1) Check fault codes - if fault code does not identify which coil has failed, REPLACE BOTH. Coil failure almost guarantees ECU failure but run car with new coil(s) - if idle control is correct - and idle control fault code does not reappear then ECU has probably survived.
Your coil packs will need to be replaced, if your lucky the ecu wont have been damaged.
Check for blocked pipes from the idle valve air intakes and also check the wiring on the idle valve, and spray some carb cleaner into the idle valve and let it soak in for about 30 mins. Then try it again. Also make sure there are no air leaks where the idle valve is fitted. It could also be a air flow meter problem.
it does sound like you have a problem on the air induction side of things, has the mechanic had a very thorough look at all the vacuum pipes and even the inlet manifold gasket, some times all that is needed is a good clean out of the air idle Control valve. Good luck.
A engine that wont idle properly sounds more like a blockage in the fuel system
what year is the car?
if it has an ecu the problem could be with one of the sensors
Design of a High Pressure Control Valve for use in a Cryocooler?
control valve which is used in missileDesign of a High Pressure Control Valve for use in a Cryocooler?
Well.....will this be a gas valve or a liquid valve?
is it an On/OFF valve or a Servo Controlled valve.
will it need to flow 10,000 CFM or just 1 cfm.
Will the gas/liquid be hydrogen, oxygen or hydrazene?
What will be the maximum pressures?
What will lbe the the rated loads on the valve during launch?
Is there a turbo pump upstream or is the flow by gravity. (i doubt it.)
wer
Well.....will this be a gas valve or a liquid valve?
is it an On/OFF valve or a Servo Controlled valve.
will it need to flow 10,000 CFM or just 1 cfm.
Will the gas/liquid be hydrogen, oxygen or hydrazene?
What will be the maximum pressures?
What will lbe the the rated loads on the valve during launch?
Is there a turbo pump upstream or is the flow by gravity. (i doubt it.)
wer
Heater control valve; Ford econoline e-150 2000 ; where is it located?
Usually in engine compartment on the right side. follow the heater hose.
Monday, February 8, 2010
Water temperature control valve?
I'm renting a duplex right now and every time I get in the shower the people that live downstairs run the water and I get either cold water or it turns to scalding hot! my question is, is it mandatory for the landlord to have the water temperature control valve installed?
I live in Trenton, Ontario if that helps any. Also where would I be able to ask a person about this if it is?? (government or something)Water temperature control valve?
Check with your local heating and ac dealer and ask them what the fix is for this problem!!There is a fix for this problem but i cant remember exactly what it is. Sorry!!Water temperature control valve?
ANTI SCALD VALVE SHOULD BE FITTED LAW IN UK
I live in Trenton, Ontario if that helps any. Also where would I be able to ask a person about this if it is?? (government or something)Water temperature control valve?
Check with your local heating and ac dealer and ask them what the fix is for this problem!!There is a fix for this problem but i cant remember exactly what it is. Sorry!!Water temperature control valve?
ANTI SCALD VALVE SHOULD BE FITTED LAW IN UK
Where is the Evac Control Purge Flow valve located on the Hyundai Accent 1999?
Under the throttle body housing,has two vacuum lines and a two wire connector.If you are going to do more of the same thing on your car I would suggest going to ALLDATA.COM
What is a throttle control valve for a 1998 chrysler concorde?
That would be the butterfly valve inside of the throttle body, it regulates the amount of air allowed into the engine.one web hosting
Who is the manufacturers of boydstun hydraulic control valve?
looks like a few companies supply these parts - don't think they MAKE them. u can probably call them and ask.
http://www.boydstuncylinders.com/
http://cfbender.com/
http://www.boydstuncylinders.com/
http://cfbender.com/
Differnce between 3 way modulating valve and motorized control valve?
Two completely different things.
Modulating valve, one which will gradually divert fluid in one direction or another. Can be manually or automatically operated.
Motorized valve, one which has an actuator, electric or pneumatic, to open, close or throttle, and connected to a control circuit.
.
Modulating valve, one which will gradually divert fluid in one direction or another. Can be manually or automatically operated.
Motorized valve, one which has an actuator, electric or pneumatic, to open, close or throttle, and connected to a control circuit.
.
Where do u locate a Idle Air Control valve in a 91 acura integra?
its located on top of the intake manifold close by the firewall. here is a link to how to clean it and where its at with pics. i need to do this to my 93 teg as well.
http://www.honda-tech.com/showthread.php鈥?/a>
http://www.honda-tech.com/showthread.php鈥?/a>
Where can I get an idle control valve for a 2004 Subaru Impreza?
I looked up at subaruparts.comWhere can I get an idle control valve for a 2004 Subaru Impreza?
Best price I found when I needed one was at SubaruGenuineParts.com from a lady named Jamie there. Even got it the day after I ordered it. If you do get a new one remember to get a new gasket too. They are sold separately. The gasket stretches over time so if you remove the old one, it may be impossible to get it back on properly.Where can I get an idle control valve for a 2004 Subaru Impreza?
What makes you think you need one? What problem are you having. If idle air control is defective you will get a check engine lite that there is a problem with the air fuel mix. The idle speed is controlled by the ecu.
Try the link below.
The dealer!
Best price I found when I needed one was at SubaruGenuineParts.com from a lady named Jamie there. Even got it the day after I ordered it. If you do get a new one remember to get a new gasket too. They are sold separately. The gasket stretches over time so if you remove the old one, it may be impossible to get it back on properly.Where can I get an idle control valve for a 2004 Subaru Impreza?
What makes you think you need one? What problem are you having. If idle air control is defective you will get a check engine lite that there is a problem with the air fuel mix. The idle speed is controlled by the ecu.
Try the link below.
The dealer!
Is there a way to test an Idle Air Control Valve to ensure it's working correctly?
the only way is to use a scan to whatch the steps.
It is measured in steps.
Hope this helps
Auto tec.........
It is measured in steps.
Hope this helps
Auto tec.........
Can a fuel gas control valve be the same size as the line size or does it have to be the next size down?
Depends on what it does. If a shut off valve, size does not matter.
If a flow control valve, depending on the number of branch lines it will have to be smaller by a suitable margin. To some extent the accuracy of control also dictates the choice.one web hosting
If a flow control valve, depending on the number of branch lines it will have to be smaller by a suitable margin. To some extent the accuracy of control also dictates the choice.
I want to control 2 ball valve actuators independantly?
I have a single air supply from a regulator set at 7 bar. I want to achieve valve actuation by having a 2 position lever switch which is panel mounted and connected to a pneumatic valve. The pneumatic valve is to supply air to the ball valve actuators. When the panel mounted switch is in one position it supplies air to the first actuator (to open it) and with the switch in the other position it cuts off air to the first actuator (so it closes) and operates the other actuator in the same manner as the first. Can this be achieved with a 5/2 valve or would I need some form of pneumatic logic?I want to control 2 ball valve actuators independantly?
Yes.
connect supply to port 1
Valve 1 to port 2
Valve 2 to port 4
3 %26amp; 5 are exhausts
See http://www.norgren.com/training/default.鈥?/a>
%26amp; down load VALVES.ZIP
Valves would have to be spring to close!
if they aren't %26amp; they are air to open %26amp; air to close then:
pipe as follows:
Supply Port 1
Valve 1 to open and valve 2 to close Port 2
Valve 1 to close and valve 2 to open Port 4
3 %26amp; 5 still exhausts!I want to control 2 ball valve actuators independantly?
Why not set-up two storage tanks with the main feed suppling both, then configure the swtich/relay to activate a release valve on each tank to activate the actuators.
It will be to long of an answere to go thru, but you have a normally closed valve and a normally open valve. So when air is supplied, one opens and the other closes. You can work something out with that depending how your set up is going to be.
This is the solenoids I am talking about.
Yes.
connect supply to port 1
Valve 1 to port 2
Valve 2 to port 4
3 %26amp; 5 are exhausts
See http://www.norgren.com/training/default.鈥?/a>
%26amp; down load VALVES.ZIP
Valves would have to be spring to close!
if they aren't %26amp; they are air to open %26amp; air to close then:
pipe as follows:
Supply Port 1
Valve 1 to open and valve 2 to close Port 2
Valve 1 to close and valve 2 to open Port 4
3 %26amp; 5 still exhausts!I want to control 2 ball valve actuators independantly?
Why not set-up two storage tanks with the main feed suppling both, then configure the swtich/relay to activate a release valve on each tank to activate the actuators.
It will be to long of an answere to go thru, but you have a normally closed valve and a normally open valve. So when air is supplied, one opens and the other closes. You can work something out with that depending how your set up is going to be.
This is the solenoids I am talking about.
Where is the idle speed control valve located on a 96mdl toyota corolla xl located?
my car has a 1.3 ltr, 12valve engine and uses a carburetor not fuel injection.Where is the idle speed control valve located on a 96mdl toyota corolla xl located?
well it isnt a valve as such but if you find the accelerator cable going to the carb there are little nuts that tension the cable
with the car running wind them back and forth untill you find the desired revs.Where is the idle speed control valve located on a 96mdl toyota corolla xl located?
why dont you try to figure out the problem rather than covering it up with a higher rate of idle, unless the idle had been slowed down in the first place.
Don't adjust the idle speed with the cable tension as Johnny advises - there's a screw on the base of the carbuerator for this.
Towards the back of the carb there's a thumb screw with a plastic head, about a centimeter in diameter. It's a little hard to get to. Turn it slowly to adjust.
well it isnt a valve as such but if you find the accelerator cable going to the carb there are little nuts that tension the cable
with the car running wind them back and forth untill you find the desired revs.Where is the idle speed control valve located on a 96mdl toyota corolla xl located?
why dont you try to figure out the problem rather than covering it up with a higher rate of idle, unless the idle had been slowed down in the first place.
Don't adjust the idle speed with the cable tension as Johnny advises - there's a screw on the base of the carbuerator for this.
Towards the back of the carb there's a thumb screw with a plastic head, about a centimeter in diameter. It's a little hard to get to. Turn it slowly to adjust.
Where is the idle speed control valve located on a 96mdl toyota corolla xl located?
my car has a 1.3 ltr, 12valve engine and uses a carburetor not fuel injection.Where is the idle speed control valve located on a 96mdl toyota corolla xl located?
well it isnt a valve as such but if you find the accelerator cable going to the carb there are little nuts that tension the cable
with the car running wind them back and forth untill you find the desired revs.Where is the idle speed control valve located on a 96mdl toyota corolla xl located?
why dont you try to figure out the problem rather than covering it up with a higher rate of idle, unless the idle had been slowed down in the first place.
Don't adjust the idle speed with the cable tension as Johnny advises - there's a screw on the base of the carbuerator for this.
Towards the back of the carb there's a thumb screw with a plastic head, about a centimeter in diameter. It's a little hard to get to. Turn it slowly to adjust.
well it isnt a valve as such but if you find the accelerator cable going to the carb there are little nuts that tension the cable
with the car running wind them back and forth untill you find the desired revs.Where is the idle speed control valve located on a 96mdl toyota corolla xl located?
why dont you try to figure out the problem rather than covering it up with a higher rate of idle, unless the idle had been slowed down in the first place.
Don't adjust the idle speed with the cable tension as Johnny advises - there's a screw on the base of the carbuerator for this.
Towards the back of the carb there's a thumb screw with a plastic head, about a centimeter in diameter. It's a little hard to get to. Turn it slowly to adjust.
Where is the IAC (idle control valve) on a pontiac grand am '98?
i can't find the iac valve, i forget exactly what it stands for , but thanks in advanceWhere is the IAC (idle control valve) on a pontiac grand am '98?
The IAC stands for Idle Air Control, and usually they are located on the throttle body.
The IAC stands for Idle Air Control, and usually they are located on the throttle body.
Where is the idle air control valve on a 1994 nissan altima?
it should be on the intake manifoldone web hosting
Where is the heater control valve located on a 1973 corvette?
good question i had a 73 vette, I think its under the dash on the passenger side I do know 1 thing for sure they dont have good heaters in them they are not cold weather cars
Where is the heater control valve in a 96 lincoln town car?
If you locate the two hoses coming from the fire wall on passengers side where heater is located and follow them you will find he valve at some point.Where is the heater control valve in a 96 lincoln town car?
0 zero, none
0 zero, none
Do I have an idle control valve problem? I'm having problems with rough idle and stalling coming from a stop.
I have a 1990 Chevy Cav. Runs fine but I do have problems with a cold engine (driving for the first 5-10 mins) when I come to a complete stop. When I try to accelerate or make a turn, the engine stalls and misses for a few seconds. Again this only happens in the morning or when the engine is cold then goes away. I suspect the ICV based on what I've read. Maybe needs to be cleaned or replaced?Do I have an idle control valve problem? I'm having problems with rough idle and stalling coming from a stop.
As a GM tech, I suggest that you check your fuel pressure first. Low fuel presssure during a cold start can cause all kinds of driveability problems that look like other components are failing. It's easy to check and it's vital info when diagnosing these kind of problems.Do I have an idle control valve problem? I'm having problems with rough idle and stalling coming from a stop.
I've been letting the car warm up for about 10 mins in the morning, and the problem has gone away. I still plan to have the fuel pressure checked.
when i had a 95 jeep cherokee i had trouble with it stalling when i slowed to make a turn and at stop lights .... it did it when it was warm too tho..... a mechanic unplugged the egr valve and it never did it again
First check the code if the check engine light is on. If no light then I would look at the cold start sensor.
you may have a heat up flap in your exhaust manifold that may stick shut or does not open all the way until the motor gets as warm as it is going to get to run normal.
replace the coolant sensor
Coolant temperature sensor is likely bad.
sounds like a low fuel pressure problem
IT SOUNDS LIKE IT TO ME BUT.............
YOU SHOULD GET THE VEHICLES COMPUTER SCANNED AND CHECK FOR ANY PROBLEMS AS WELL AS CODES AND THEN YOU WILL HAVE A GOOD IDEA ON WHAT THE PROBLEM TRULY IS.
TRY FINDING AN INDEPENDENT SHOP INSTEAD OF THE DEALER OR A CHAIN STORE BECAUSE YOU WILL BE OVERALL MORE PLEASED WITH THE FINDINGS AND THE SERVICE.
LEAVE IT THERE WITH THEM SO THAT THEY CAN FIND THE PROBLEM FOR YOU, IT WILL BE A LOT BETTER THAN JUST REPLACING PART AFTER PART AND NOT DOING ANY GOOD.
As a GM tech, I suggest that you check your fuel pressure first. Low fuel presssure during a cold start can cause all kinds of driveability problems that look like other components are failing. It's easy to check and it's vital info when diagnosing these kind of problems.Do I have an idle control valve problem? I'm having problems with rough idle and stalling coming from a stop.
I've been letting the car warm up for about 10 mins in the morning, and the problem has gone away. I still plan to have the fuel pressure checked.
Report Abuse
when i had a 95 jeep cherokee i had trouble with it stalling when i slowed to make a turn and at stop lights .... it did it when it was warm too tho..... a mechanic unplugged the egr valve and it never did it again
First check the code if the check engine light is on. If no light then I would look at the cold start sensor.
you may have a heat up flap in your exhaust manifold that may stick shut or does not open all the way until the motor gets as warm as it is going to get to run normal.
replace the coolant sensor
Coolant temperature sensor is likely bad.
sounds like a low fuel pressure problem
IT SOUNDS LIKE IT TO ME BUT.............
YOU SHOULD GET THE VEHICLES COMPUTER SCANNED AND CHECK FOR ANY PROBLEMS AS WELL AS CODES AND THEN YOU WILL HAVE A GOOD IDEA ON WHAT THE PROBLEM TRULY IS.
TRY FINDING AN INDEPENDENT SHOP INSTEAD OF THE DEALER OR A CHAIN STORE BECAUSE YOU WILL BE OVERALL MORE PLEASED WITH THE FINDINGS AND THE SERVICE.
LEAVE IT THERE WITH THEM SO THAT THEY CAN FIND THE PROBLEM FOR YOU, IT WILL BE A LOT BETTER THAN JUST REPLACING PART AFTER PART AND NOT DOING ANY GOOD.
I have a 1989 ford econovan. where would i find the heater control valve and how do i know if its faulty?
My fans are working. the problem i have found so far is when the engine heats up, both heater hoses remain cold. even right into the heater core. thanksI have a 1989 ford econovan. where would i find the heater control valve and how do i know if its faulty?
the valve should be located on the passenger side of the engine bay just before the hoses go through the firewall. once you find it have some one switch the heat on and if the valve does not move remove it and clean it up because on those older vehicles they usually just get rusted up or the cable running to them gets pulled off or fails
the valve should be located on the passenger side of the engine bay just before the hoses go through the firewall. once you find it have some one switch the heat on and if the valve does not move remove it and clean it up because on those older vehicles they usually just get rusted up or the cable running to them gets pulled off or fails
Have check enegine light 1443 where is the evaporative emission vapor control valve at on a 1998 cobra mustang
usually we find that on those the flow sensor that is in line with the vapor control valve gets clogged and sets the code.
You have to find the Evap canister which if I remember is in the front of this vehicle, and there will be a hose leading to the intake of the engine.. there will be a brass colored valve and a black sensor piece in the line along the way.. that is your problem.
Ford had a fix on some vehicles by having you replace the rubber line, the valve and flow sensor as an assembly with a Ford base part number of 9c987
These were a bear to diagnose 10 years ago but in the 10 years, evap has become easier but usually without a shop of tools however it's almost impossible without throwing the kitchen sink at a problem.Have check enegine light 1443 where is the evaporative emission vapor control valve at on a 1998 cobra mustang
a 1443 is a very hard code to get rid of, the evap system controls gas vapors, vapors are not vented to the atmosphere they are kept in the fuel system and burned, there are numerous things that can cause this code and it such a complicated system that joe average will not fix it, ford has test equipment that is needed to fix this - the control valve probably isnt the problem, it can be a pinhole in a vapor line, a bad gascap, see the evap system draws a vacuum on the fuel system, if it cant achive a certain vacuum it sets the 1443 code, i think u will be further ahead to take it to a dealer or ignore the lite, the test equipment needed is so high dollar equipment to buy its not worth your time, i was a ford certified tech and have fought this code many times and they are a nightmare, its a simple system but its very complicated in how it works, someone over engineered this system and its a hard code to get rid of, sorry no easy fix for this code, take it to your dealer
You have to find the Evap canister which if I remember is in the front of this vehicle, and there will be a hose leading to the intake of the engine.. there will be a brass colored valve and a black sensor piece in the line along the way.. that is your problem.
Ford had a fix on some vehicles by having you replace the rubber line, the valve and flow sensor as an assembly with a Ford base part number of 9c987
These were a bear to diagnose 10 years ago but in the 10 years, evap has become easier but usually without a shop of tools however it's almost impossible without throwing the kitchen sink at a problem.Have check enegine light 1443 where is the evaporative emission vapor control valve at on a 1998 cobra mustang
a 1443 is a very hard code to get rid of, the evap system controls gas vapors, vapors are not vented to the atmosphere they are kept in the fuel system and burned, there are numerous things that can cause this code and it such a complicated system that joe average will not fix it, ford has test equipment that is needed to fix this - the control valve probably isnt the problem, it can be a pinhole in a vapor line, a bad gascap, see the evap system draws a vacuum on the fuel system, if it cant achive a certain vacuum it sets the 1443 code, i think u will be further ahead to take it to a dealer or ignore the lite, the test equipment needed is so high dollar equipment to buy its not worth your time, i was a ford certified tech and have fought this code many times and they are a nightmare, its a simple system but its very complicated in how it works, someone over engineered this system and its a hard code to get rid of, sorry no easy fix for this code, take it to your dealer
What are the symptoms of a bad idle control valve?
87 volks cabriolet...hard to start but when running..runs roughWhat are the symptoms of a bad idle control valve?
Will tend to stall when cold, especially when putting the car into gear. You'll probably have to keep your foot on the gas to keep it from stalling at idle if ambient is cold.
It will also usually ';hunt'; for an appropriate idle speed while idling, even when warmed up.
As I recall, with just the key on (not engine running) you will feel this thing (with your hand) ';humming';. Further, if this is a 3 wire gizmo, you should be able to find continuity with a meter between the center terminal and each of the two outside terminals of the valve. On the control side, you should get about 10V between the center terminal (positive) and each of the two outside terminals (controlled grounds).
This replaces the old manually adjusted ';air idle valve'; on a carb.one web hosting
Will tend to stall when cold, especially when putting the car into gear. You'll probably have to keep your foot on the gas to keep it from stalling at idle if ambient is cold.
It will also usually ';hunt'; for an appropriate idle speed while idling, even when warmed up.
As I recall, with just the key on (not engine running) you will feel this thing (with your hand) ';humming';. Further, if this is a 3 wire gizmo, you should be able to find continuity with a meter between the center terminal and each of the two outside terminals of the valve. On the control side, you should get about 10V between the center terminal (positive) and each of the two outside terminals (controlled grounds).
This replaces the old manually adjusted ';air idle valve'; on a carb.
Where is the heater control valve located on my 2001 mitsubishi eclipse?
Well, I cant really help you with your problem but I have a question for you. I'm thinking about buying a 2003 eclipse gt but my dad wants consumer reviews and the only recent ones i can find are from 2002-2004.
What's your opinion of the car and do you recommend it? About how many miles can you get out of it before it starts giving you mechanical problems?
http://answers.yahoo.com/question/index;_ylt=Aukz5nEd6UR6TFVgw04_6YEazKIX;_ylv=3?qid=20091016172541AAu9pwi
Reply to it on there please :)
Thank you!Where is the heater control valve located on my 2001 mitsubishi eclipse?
whats that
What's your opinion of the car and do you recommend it? About how many miles can you get out of it before it starts giving you mechanical problems?
http://answers.yahoo.com/question/index;_ylt=Aukz5nEd6UR6TFVgw04_6YEazKIX;_ylv=3?qid=20091016172541AAu9pwi
Reply to it on there please :)
Thank you!Where is the heater control valve located on my 2001 mitsubishi eclipse?
whats that
Where is the IDLE AIR CONTROL VALVE located on a 1991 mitsubishi galant?
Under the throttle body where the air cleaner tube clamps on.
How to calibrate a digital control valve in offline having foundation fieldbus ?
hi friends
i want to know about the calibration technque of foundation fieldbus based control valve by a analog sourceHow to calibrate a digital control valve in offline having foundation fieldbus ?
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United States Patent 5431182
Smart valve positioner
US Patent Issued on July 11, 1995
Inventor(s)
Gregory C. Brown
Assignee
Rosemount, Inc.
Application
No. 230492 filed on 1994-04-20
Current US Class
137/85 , With counter-balancing pressure feedback to the modulating device 137/487.5 Electrically actuated valve
Field of Search
137/487.5 , Electrically actuated valve 137/85 With counter-balancing pressure feedback to the modulating device
Examiners
Primary: Gerald A Michalsky
Attorney, Agent or Firm
Westman, Champlin %26amp; Kelly
US Patent References
4712173
Multicontrol process control system
Issued on: December 8, 1987
Inventor: Fujiwara, et al.
Abstract Claims Description Full Text
Description
BACKGROUND OF THE INVENTION
The present invention relates to a valve positioner for controlling a valve which affects a process variable. More specifically, the present invention relates to a valve positioner having a microprocessor.
Various types of positioners are used in the process control industry. Some positioners are mechanically coupled to an actuator while some incorporate the positioner within the actuator. The actuator provides means for physically positioning the valve and may be electric, hydraulic or pneumatic. Electric actuators have a current signal which drives a motor which positions the valve. Hydraulic actuators have oil-filled means for positioning the valve. By far the most common in the process control industry, a pneumatic actuator has a piston or a combination of a spring and diaphragm which position the valve. Depending on the application and the level of control integration, positioners receive several types of input from a controller which are representative of the desired valve position. One type is a current input having a 4-20 mA or a 10-50 mA magnitude, a second is a digital signal superimposed on the current signal and a third is a fully digital input such as Fieldbus or Hodbus.RTM.. Alternatively, the positioner may receive a 3-15 or 6-30 pound per square inch (PSI) pneumatic input representative of the desired valve position. Depending on the level of integration and the application as well, positioners have different types of outputs. Some positioners provide an output current to an electric actuator motor, while still others have a fast responding hydraulic output. The most common type of positioner output is a 0-200 PSI pneumatic output. Positioner, as the word is used in this application, includes all these field mounted instruments, including the various inputs and outputs, and their respective means for positioning valves, if applicable. U.S. Pat. Nos. 4,665,938 and 5,197,328 are examples of valve positioners.
In the most common case of a spring and diaphragm actuator, the diaphragm deflects with the pressure delivered by the positioner, thereby exerting a force or torque on a control valve stem or rotary member, respectively, so as to change the position of the valve. Many positioners have a mechanical or an electronic position sensor to provide a position signal which is fed back into a microprocessor-based control section of the positioner. No matter what the specific means are for delivering force to position a valve, positioners having microprocessors are known. Existing microprocessor-based positioners provide good loop dynamic response, but have a limited band-width so that their usage is limited to slow control loops such as one which controls level in a tank or temperature in a reactor.
With the introduction of microprocessors into valve positioners, the microprocessor is being called on to perform increasingly complex functions, resulting in higher overall power requirements for the positioner. In control systems using, for example, the 4-20 mA, 10-50 mA, Fieldbus and Modbus.RTM. protocols, the operating power of the positioner is limited, since the positioner operates exclusively on the power supplied by the control loop. This limitation has placed an upper limit on the amount of computation and the clock frequency (dynamic response) of the microprocessor in the valve positioner. As technology has advanced, it has been possible to obtain more computational power from a microprocessor without increasing the electrical power requirements. However, the desire to increase control and performance of valve positioners has outpaced the ability of the microprocessor to deliver the requirements under the aforementioned electrical power constraints. A low Dower positioner with wide bandwidths under computer control is needed.
SUMMARY OF THE INVENTION
A valve positioner assembly includes a valve positioner which provides a control pressure to a pneumatic actuator operably coupled to a valve. The valve positioner has an interface coupled to a process control loop for receiving a desired valve position and an analog FID controller which generates a command output for controlling the value, based upon the desired valve position which and a sensed valve position. A microprocessor calculates PID constants, each of which control a variable impedance in the analog PID controller. The digital control signal is stored in a latch and is periodically updated by the microprocessor. In one embodiment, first and second power supplies provide power to the positioner as received over the control loop. The supplies are connected in series.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a control loop including a valve positioner in accordance with the invention.
FIG. 2 is a block diagram of the valve positioner of FIG. 1.
FIG. 3 is a block diagram of control circuitry of FIG. 2.
FIG. 4 is a simplified electrical schematic diagram of a PID controller of FIG. 3.
FIG. 5 is a simplified electrical schematic diagram of power supply circuitry used to power the valve positioner of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a process control loop generally at 10 which typically includes two-wire transmitter 12 which senses a process variable representative of process 14, a controller 16 which may reside in a control room 18 and receives the sensed process variable from transmitter 12 and valve positioner assembly 20 which receives a desired valve setpoint from controller 16 and which controls a physical variable in process 14. Transmitter 12 provides the sensed process variable over a first two-wire circuit formed by cabling 22a and 22b, and controller 16 communicates with positioner assembly 20 over loop 24a and 24b.
A valve positioner circuit 26 in positioner assembly 20 receives a 4-20 mA current representative of the desired valve position, and provides a 3-15 psi pneumatic output 28 to pneumatic actuator 30. Actuator 30 controls valve 32 which controls a flow in process 14. Actuator 30 provides pressure and position feedback 34 to positioner 26.
In FIG. 2, positioner 26 includes communications interface 40 for receiving a 4-20 mA current signal representative of the desired position of valve 32 from controller 16 over wires or a digital setpoint 24a/24b. Interface 40 also provides power supply outputs VS1 and VS2 generated from loop 24a/24b. Circuit 24a/24b can also be a three or four wire circuit as used in the process control industry. Pneumatic output 28 of positioner 26 is connected to valve 32 through actuator 30 so that the applied pressure deflects diaphragm 42 which exerts a force on spring 44 and moves stem 46 within valve 32. Plug 48 mates with stem 46 to slidably obstruct a passageway in valve 32 and control the flow of fluid in pipe 50. Other types of valves, such as rotary valves, may also be used.
Microprocessor 52, which is clocked by oscillator 56, includes on-chip program and storage memory 54 and is preferably made in a low power technology such as CMOS. Microprocessor 52 is connected to a latch and decode circuit 58 and analog-to-digital converter (A/D) 60. Analog-to-digital converter 60 couples to multiplexer MUX 62.
Sum-node circuit 64 is coupled to interface/power supply 40 and receives a signal representative of the desired valve position from interface 40. Sum-node 64 receives three signals from latch and decode circuitry 58: span, zero and input roll/off control. Sum-node 64 provides a position request signal to controller 66.
Control circuit 66 receives four digital control constants from latch and decode circuit 58 representative of the proportional gain signal P), the integral (I), and the derivative (D), along with a position request adjustment signal. The PID control equation which analog circuit 66 implements is given by: ##EQU1## where e(t) is the difference between the desired valve position and the current valve position, t is time, Co is the desired control (command) Output.
Control circuit 66 also receives feedback 34 from position and actuator pressure feedback circuitry 68 and 76. Control circuit 66 provides a control signal to driver circuitry 70 which also receives a pneumatic slew rate control input from circuitry 58. I/P transducer 78 (which includes a booster stage) regulates pressurized air from pneumatic source 80 as a function of the coil drive voltage signal.
Position sensor 82 is coupled to valve stem 46 and temperature sensor 84 is positioned proximate to valve stem 46. Signals from sensors 82 and 84 are provided to multiplexer 62 through position interface 86 and temperature interface 88, respectively. Circuit 68 outputs a temperature compensated position signal to control circuit 66. Actuator pressure interface 76 receives a feedback signal 34 from pressure sensor 90, which measures the pressure in pressure line 28 and provides an input to multiplexer 62 and feedback to control circuit 66. Microprocessor 52 periodically samples the inputs to MUX 62 through A/D converter 60.
There is a continuing need to improve the accuracy with which control valves are positioned. Existing valve positioning devices with a microprocessor allow improved control valve positioning. Additionally, the microprocessor can be used to monitor performance and diagnostics of the control valve. The benefits of an electronic microprocessor-based positioner are extensive and provide many advantages in controlling operation of a valve.
In the present invention, power reduction is achieved by incorporating analog circuitry controlled by microprocessor 52. The analog circuitry performs some of the computationally intensive functions (notably the PID control equation) otherwise performed by microprocessor 52, thus allowing microprocessor 52 to perform other functions without sacrificing control system band width. Thus, the invention provides low power PID control at high speed and wide band-width.
Microprocessor 52 periodically updates the constants of the PID equation. In one embodiment, there are four cases which affect the update rate: calibration, startup, steady state operation, and response to transients. During startup, an initial set of constants is chosen based on, for example, past startups or predetermined values. During steady state operation, the constants are infrequently updated but with a high level of accuracy and control. When responding to abrupt changes, the constants are frequently updated. Typically, when the constants need frequent updating, their accuracy is less important thus allowing faster processing. For example, updates may occur every 0.1 to 0.25 seconds. As the values get closer to their final value, the updating may be less frequent allowing microprocessor 52 greater time for higher accuracy.
Analog circuitry includes sum-node/span and zero adjustment circuitry 64, control block 66, position feedback circuitry 68, driver circuitry 70 and diagnostic circuitry 72. The control equation implemented in the analog circuitry is determined by microprocessor 52 which provides digital control signals to the circuitry. Circuit 66 outputs a command output according to Equation 1.
FIG. 3 is a simplified schematic diagram showing a portion of control circuit 66. Circuit 66 includes sum-node 100, PID circuitry 102 and variable gain circuitry 104. Sum-node 100 receives a representation of a desired valve position from circuitry 64, an adjustment input from latch and decode circuitry 58 which allows microprocessor 52 to adjust the request, and a position feedback signal from circuitry 68. Node 100 sums these signals and provides them to PID circuitry 102. PID circuitry 102 receives the latched P, I and D digital control signals from circuitry 58 and provides a control signal output to variable gain circuitry 104. Gain of circuitry 104 is controlled by a pressure feedback output from pressure feedback circuitry 76 and provides a control signal output to driver 70.
FIG. 4 is a simplified schematic diagram of PID circuit 102 in accordance with the present invention. PID circuitry 102 includes operational amplifier 110, analog switch 112, analog switch 114 and analog switch 116. Switches 112-116, respectively, control the P, I and D constants of circuit 102. The inverting input of OPAMP 110 connects to resistor 118 which connects to node 100 through resistor 120. The non-inverting input to OPAMP 110 is coupled to signal ground and the output couples to driver 70. Analog switch 112 is connected in series with capacitor 122 across resistor 120. Analog switches 112-116 include resistors R1 -R8 and field effect transistors Q1 -Q8. Switch 116 controls P, switch 114 and capacitor 123 control I and switch 112 and capacitor 122 control D.
The gates of FETs Q1 -Q8 are coupled to circuits 58a, 58b and 58c of latch and decode circuitry 58 shown in FIG. 2. Latch and decode circuitry 58a, 58b and 58c receives P, I, and D inputs from microprocessor 52. For example, decode 58c receives a digital value to the derivative constant (D) from microprocessor 52. Decode and latch circuit 58c decodes this value into a combination of analog voltage signals provided to the gates of transistors Q1 -Q8, thereby selectively controlling whether each of transistors Q1 -Q8 is either on or off. Decoder and latch circuitry 58c latches this data following the decoding step so that microprocessor 52 does not continuously supply digital control signals to decoder 58c. Based upon the combination of transistors Q1 -Q8 turned on, the resistance provided by analog switch 112 is controlled to determine the derivative constant of PID circuit 102. Decoders 58a and 58b work in a similar manner whereby the proportional (P) and integral (I) constants are output by microprocessor 52 and selectively modify resistances 114 and 116, respectively.
Valve positioner 20 operates using a hybrid of digital and analog circuitry and thereby achieves advantages of both types of circuitry. Analog circuity performs much of the control which requires high speed and wide band-width so that microprocessor 52 operates with reduced power. However, microprocessor 52 controls operation of analog circuity through latch and decode 58 such that control of valve 32 is not sacrificed. Referring to FIG. 2, microprocessor 52 receives a desired position request from two-wire control loop 24a/24b and feedback from analog-to-digital converter 60. Based upon these inputs, microprocessor 52 configures the analog circuitry by supplying the digital control constants to latch and decode circuitry 56. FIG. 4 is an example of PID circuitry 102 which operates under control of microprocessor 52. Microprocessor 52 also controls sum node/zero and span circuity 64, the slew rate of actuator drive 70, and position request adjustment to circuit 66 of FIG. 3. Although the specific example shows adjustment of a resistance value through switches 112-116, other analog parameters can be adjusted by microprocessor 52 such as current, inductance, capacitance, etc., using similar circuitry in accordance with the invention. Standard circuits in most engineering applications handbooks can be controlled using the present techniques. For example, a voltage controlled gain circuit is controlled by providing a voltage output from A/D converter 60 to the circuit voltage input.
FIG. 5 is a simplified diagram of valve positioner 26 showing a power supply connection in accordance with the present invention. Positioner 26 is shown receiving all electrical power through loop 24a/24b, and does not require an additional power source. FIG. 5 shows interface 40 which includes input/output circuity 140, a 4 volt power supply 142 and a 9.5 volt power supply 144 connected in series with two-wire loop 24a/24b. Four volt power supply 142 provides voltage VS1 for operation of microprocessor 52 and other digital circuitry. Supply 144 provides VS2, a 9.5 volt regulated power supply for analog circuity. I/O circuitry 140 receives the desired position signal over loop 24a/24b in accordance with techniques known in the process control industry. In the embodiment shown in FIG. 5, decode circuitry 58 and sensor interface circuitry are powered by 9.5 volt power supply 144. The circuitry of FIG. 5 shows ';stacked'; power supplies which use almost the entire 15 volt maximum allowed between wires 24a and 24b. If the stacked power supply shown in FIG. 5 is employed, level shifting circuitry (not shown) is necessary to shift levels of various signals.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, actuators other than pneumatic based actuators may be employed, and decode circuitry 58 may comprise a ROM.
* * * * *
Quotables
';I hate what they've done to my child...I would never let my own children watch it. ';
Vladimir Zworykin, television pioneer; Talking about an invention in which he played a critical role.
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i want to know about the calibration technque of foundation fieldbus based control valve by a analog sourceHow to calibrate a digital control valve in offline having foundation fieldbus ?
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United States Patent 5431182
Smart valve positioner
US Patent Issued on July 11, 1995
Inventor(s)
Gregory C. Brown
Assignee
Rosemount, Inc.
Application
No. 230492 filed on 1994-04-20
Current US Class
137/85 , With counter-balancing pressure feedback to the modulating device 137/487.5 Electrically actuated valve
Field of Search
137/487.5 , Electrically actuated valve 137/85 With counter-balancing pressure feedback to the modulating device
Examiners
Primary: Gerald A Michalsky
Attorney, Agent or Firm
Westman, Champlin %26amp; Kelly
US Patent References
4712173
Multicontrol process control system
Issued on: December 8, 1987
Inventor: Fujiwara, et al.
Abstract Claims Description Full Text
Description
BACKGROUND OF THE INVENTION
The present invention relates to a valve positioner for controlling a valve which affects a process variable. More specifically, the present invention relates to a valve positioner having a microprocessor.
Various types of positioners are used in the process control industry. Some positioners are mechanically coupled to an actuator while some incorporate the positioner within the actuator. The actuator provides means for physically positioning the valve and may be electric, hydraulic or pneumatic. Electric actuators have a current signal which drives a motor which positions the valve. Hydraulic actuators have oil-filled means for positioning the valve. By far the most common in the process control industry, a pneumatic actuator has a piston or a combination of a spring and diaphragm which position the valve. Depending on the application and the level of control integration, positioners receive several types of input from a controller which are representative of the desired valve position. One type is a current input having a 4-20 mA or a 10-50 mA magnitude, a second is a digital signal superimposed on the current signal and a third is a fully digital input such as Fieldbus or Hodbus.RTM.. Alternatively, the positioner may receive a 3-15 or 6-30 pound per square inch (PSI) pneumatic input representative of the desired valve position. Depending on the level of integration and the application as well, positioners have different types of outputs. Some positioners provide an output current to an electric actuator motor, while still others have a fast responding hydraulic output. The most common type of positioner output is a 0-200 PSI pneumatic output. Positioner, as the word is used in this application, includes all these field mounted instruments, including the various inputs and outputs, and their respective means for positioning valves, if applicable. U.S. Pat. Nos. 4,665,938 and 5,197,328 are examples of valve positioners.
In the most common case of a spring and diaphragm actuator, the diaphragm deflects with the pressure delivered by the positioner, thereby exerting a force or torque on a control valve stem or rotary member, respectively, so as to change the position of the valve. Many positioners have a mechanical or an electronic position sensor to provide a position signal which is fed back into a microprocessor-based control section of the positioner. No matter what the specific means are for delivering force to position a valve, positioners having microprocessors are known. Existing microprocessor-based positioners provide good loop dynamic response, but have a limited band-width so that their usage is limited to slow control loops such as one which controls level in a tank or temperature in a reactor.
With the introduction of microprocessors into valve positioners, the microprocessor is being called on to perform increasingly complex functions, resulting in higher overall power requirements for the positioner. In control systems using, for example, the 4-20 mA, 10-50 mA, Fieldbus and Modbus.RTM. protocols, the operating power of the positioner is limited, since the positioner operates exclusively on the power supplied by the control loop. This limitation has placed an upper limit on the amount of computation and the clock frequency (dynamic response) of the microprocessor in the valve positioner. As technology has advanced, it has been possible to obtain more computational power from a microprocessor without increasing the electrical power requirements. However, the desire to increase control and performance of valve positioners has outpaced the ability of the microprocessor to deliver the requirements under the aforementioned electrical power constraints. A low Dower positioner with wide bandwidths under computer control is needed.
SUMMARY OF THE INVENTION
A valve positioner assembly includes a valve positioner which provides a control pressure to a pneumatic actuator operably coupled to a valve. The valve positioner has an interface coupled to a process control loop for receiving a desired valve position and an analog FID controller which generates a command output for controlling the value, based upon the desired valve position which and a sensed valve position. A microprocessor calculates PID constants, each of which control a variable impedance in the analog PID controller. The digital control signal is stored in a latch and is periodically updated by the microprocessor. In one embodiment, first and second power supplies provide power to the positioner as received over the control loop. The supplies are connected in series.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a control loop including a valve positioner in accordance with the invention.
FIG. 2 is a block diagram of the valve positioner of FIG. 1.
FIG. 3 is a block diagram of control circuitry of FIG. 2.
FIG. 4 is a simplified electrical schematic diagram of a PID controller of FIG. 3.
FIG. 5 is a simplified electrical schematic diagram of power supply circuitry used to power the valve positioner of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a process control loop generally at 10 which typically includes two-wire transmitter 12 which senses a process variable representative of process 14, a controller 16 which may reside in a control room 18 and receives the sensed process variable from transmitter 12 and valve positioner assembly 20 which receives a desired valve setpoint from controller 16 and which controls a physical variable in process 14. Transmitter 12 provides the sensed process variable over a first two-wire circuit formed by cabling 22a and 22b, and controller 16 communicates with positioner assembly 20 over loop 24a and 24b.
A valve positioner circuit 26 in positioner assembly 20 receives a 4-20 mA current representative of the desired valve position, and provides a 3-15 psi pneumatic output 28 to pneumatic actuator 30. Actuator 30 controls valve 32 which controls a flow in process 14. Actuator 30 provides pressure and position feedback 34 to positioner 26.
In FIG. 2, positioner 26 includes communications interface 40 for receiving a 4-20 mA current signal representative of the desired position of valve 32 from controller 16 over wires or a digital setpoint 24a/24b. Interface 40 also provides power supply outputs VS1 and VS2 generated from loop 24a/24b. Circuit 24a/24b can also be a three or four wire circuit as used in the process control industry. Pneumatic output 28 of positioner 26 is connected to valve 32 through actuator 30 so that the applied pressure deflects diaphragm 42 which exerts a force on spring 44 and moves stem 46 within valve 32. Plug 48 mates with stem 46 to slidably obstruct a passageway in valve 32 and control the flow of fluid in pipe 50. Other types of valves, such as rotary valves, may also be used.
Microprocessor 52, which is clocked by oscillator 56, includes on-chip program and storage memory 54 and is preferably made in a low power technology such as CMOS. Microprocessor 52 is connected to a latch and decode circuit 58 and analog-to-digital converter (A/D) 60. Analog-to-digital converter 60 couples to multiplexer MUX 62.
Sum-node circuit 64 is coupled to interface/power supply 40 and receives a signal representative of the desired valve position from interface 40. Sum-node 64 receives three signals from latch and decode circuitry 58: span, zero and input roll/off control. Sum-node 64 provides a position request signal to controller 66.
Control circuit 66 receives four digital control constants from latch and decode circuit 58 representative of the proportional gain signal P), the integral (I), and the derivative (D), along with a position request adjustment signal. The PID control equation which analog circuit 66 implements is given by: ##EQU1## where e(t) is the difference between the desired valve position and the current valve position, t is time, Co is the desired control (command) Output.
Control circuit 66 also receives feedback 34 from position and actuator pressure feedback circuitry 68 and 76. Control circuit 66 provides a control signal to driver circuitry 70 which also receives a pneumatic slew rate control input from circuitry 58. I/P transducer 78 (which includes a booster stage) regulates pressurized air from pneumatic source 80 as a function of the coil drive voltage signal.
Position sensor 82 is coupled to valve stem 46 and temperature sensor 84 is positioned proximate to valve stem 46. Signals from sensors 82 and 84 are provided to multiplexer 62 through position interface 86 and temperature interface 88, respectively. Circuit 68 outputs a temperature compensated position signal to control circuit 66. Actuator pressure interface 76 receives a feedback signal 34 from pressure sensor 90, which measures the pressure in pressure line 28 and provides an input to multiplexer 62 and feedback to control circuit 66. Microprocessor 52 periodically samples the inputs to MUX 62 through A/D converter 60.
There is a continuing need to improve the accuracy with which control valves are positioned. Existing valve positioning devices with a microprocessor allow improved control valve positioning. Additionally, the microprocessor can be used to monitor performance and diagnostics of the control valve. The benefits of an electronic microprocessor-based positioner are extensive and provide many advantages in controlling operation of a valve.
In the present invention, power reduction is achieved by incorporating analog circuitry controlled by microprocessor 52. The analog circuitry performs some of the computationally intensive functions (notably the PID control equation) otherwise performed by microprocessor 52, thus allowing microprocessor 52 to perform other functions without sacrificing control system band width. Thus, the invention provides low power PID control at high speed and wide band-width.
Microprocessor 52 periodically updates the constants of the PID equation. In one embodiment, there are four cases which affect the update rate: calibration, startup, steady state operation, and response to transients. During startup, an initial set of constants is chosen based on, for example, past startups or predetermined values. During steady state operation, the constants are infrequently updated but with a high level of accuracy and control. When responding to abrupt changes, the constants are frequently updated. Typically, when the constants need frequent updating, their accuracy is less important thus allowing faster processing. For example, updates may occur every 0.1 to 0.25 seconds. As the values get closer to their final value, the updating may be less frequent allowing microprocessor 52 greater time for higher accuracy.
Analog circuitry includes sum-node/span and zero adjustment circuitry 64, control block 66, position feedback circuitry 68, driver circuitry 70 and diagnostic circuitry 72. The control equation implemented in the analog circuitry is determined by microprocessor 52 which provides digital control signals to the circuitry. Circuit 66 outputs a command output according to Equation 1.
FIG. 3 is a simplified schematic diagram showing a portion of control circuit 66. Circuit 66 includes sum-node 100, PID circuitry 102 and variable gain circuitry 104. Sum-node 100 receives a representation of a desired valve position from circuitry 64, an adjustment input from latch and decode circuitry 58 which allows microprocessor 52 to adjust the request, and a position feedback signal from circuitry 68. Node 100 sums these signals and provides them to PID circuitry 102. PID circuitry 102 receives the latched P, I and D digital control signals from circuitry 58 and provides a control signal output to variable gain circuitry 104. Gain of circuitry 104 is controlled by a pressure feedback output from pressure feedback circuitry 76 and provides a control signal output to driver 70.
FIG. 4 is a simplified schematic diagram of PID circuit 102 in accordance with the present invention. PID circuitry 102 includes operational amplifier 110, analog switch 112, analog switch 114 and analog switch 116. Switches 112-116, respectively, control the P, I and D constants of circuit 102. The inverting input of OPAMP 110 connects to resistor 118 which connects to node 100 through resistor 120. The non-inverting input to OPAMP 110 is coupled to signal ground and the output couples to driver 70. Analog switch 112 is connected in series with capacitor 122 across resistor 120. Analog switches 112-116 include resistors R1 -R8 and field effect transistors Q1 -Q8. Switch 116 controls P, switch 114 and capacitor 123 control I and switch 112 and capacitor 122 control D.
The gates of FETs Q1 -Q8 are coupled to circuits 58a, 58b and 58c of latch and decode circuitry 58 shown in FIG. 2. Latch and decode circuitry 58a, 58b and 58c receives P, I, and D inputs from microprocessor 52. For example, decode 58c receives a digital value to the derivative constant (D) from microprocessor 52. Decode and latch circuit 58c decodes this value into a combination of analog voltage signals provided to the gates of transistors Q1 -Q8, thereby selectively controlling whether each of transistors Q1 -Q8 is either on or off. Decoder and latch circuitry 58c latches this data following the decoding step so that microprocessor 52 does not continuously supply digital control signals to decoder 58c. Based upon the combination of transistors Q1 -Q8 turned on, the resistance provided by analog switch 112 is controlled to determine the derivative constant of PID circuit 102. Decoders 58a and 58b work in a similar manner whereby the proportional (P) and integral (I) constants are output by microprocessor 52 and selectively modify resistances 114 and 116, respectively.
Valve positioner 20 operates using a hybrid of digital and analog circuitry and thereby achieves advantages of both types of circuitry. Analog circuity performs much of the control which requires high speed and wide band-width so that microprocessor 52 operates with reduced power. However, microprocessor 52 controls operation of analog circuity through latch and decode 58 such that control of valve 32 is not sacrificed. Referring to FIG. 2, microprocessor 52 receives a desired position request from two-wire control loop 24a/24b and feedback from analog-to-digital converter 60. Based upon these inputs, microprocessor 52 configures the analog circuitry by supplying the digital control constants to latch and decode circuitry 56. FIG. 4 is an example of PID circuitry 102 which operates under control of microprocessor 52. Microprocessor 52 also controls sum node/zero and span circuity 64, the slew rate of actuator drive 70, and position request adjustment to circuit 66 of FIG. 3. Although the specific example shows adjustment of a resistance value through switches 112-116, other analog parameters can be adjusted by microprocessor 52 such as current, inductance, capacitance, etc., using similar circuitry in accordance with the invention. Standard circuits in most engineering applications handbooks can be controlled using the present techniques. For example, a voltage controlled gain circuit is controlled by providing a voltage output from A/D converter 60 to the circuit voltage input.
FIG. 5 is a simplified diagram of valve positioner 26 showing a power supply connection in accordance with the present invention. Positioner 26 is shown receiving all electrical power through loop 24a/24b, and does not require an additional power source. FIG. 5 shows interface 40 which includes input/output circuity 140, a 4 volt power supply 142 and a 9.5 volt power supply 144 connected in series with two-wire loop 24a/24b. Four volt power supply 142 provides voltage VS1 for operation of microprocessor 52 and other digital circuitry. Supply 144 provides VS2, a 9.5 volt regulated power supply for analog circuity. I/O circuitry 140 receives the desired position signal over loop 24a/24b in accordance with techniques known in the process control industry. In the embodiment shown in FIG. 5, decode circuitry 58 and sensor interface circuitry are powered by 9.5 volt power supply 144. The circuitry of FIG. 5 shows ';stacked'; power supplies which use almost the entire 15 volt maximum allowed between wires 24a and 24b. If the stacked power supply shown in FIG. 5 is employed, level shifting circuitry (not shown) is necessary to shift levels of various signals.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, actuators other than pneumatic based actuators may be employed, and decode circuitry 58 may comprise a ROM.
* * * * *
Quotables
';I hate what they've done to my child...I would never let my own children watch it. ';
Vladimir Zworykin, television pioneer; Talking about an invention in which he played a critical role.
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How to calculate anti surge flow for compressor for pipe and control valve sizing?
There is a minimum flow rate that must be maintained in order to keep a centrifugal compressor out of surge. That rate is shown on the compressor performance graph. It varies with compressor head.
There is a good discussion of this at the following site:
http://www.dresser-rand.com/controls/sc0鈥?/a>
There is a good discussion of this at the following site:
http://www.dresser-rand.com/controls/sc0鈥?/a>
IDLE problem dad has 2001 dodge neon check air idle control valve that's fine could it the coil pack?
lol idle problem is it the coil pack or something els going i check it with a computer scan tool nothig came upIDLE problem dad has 2001 dodge neon check air idle control valve that's fine could it the coil pack?
check plugs doesnt take much for them to get fouled,or wires they are famous for that.IDLE problem dad has 2001 dodge neon check air idle control valve that's fine could it the coil pack?
like the other poster said check the plugs in it those will get some wear on them and cause this to happen,also check and make sure its getting a good fuel supply,any lack of fuel will cause this,id almost bet that it will turn out to be the plugs or a filter clogged up real bad,even a dirty air filter will cause that to happen,good luck.,,PS if it has miss fire in it at lower speeds and on a hard climb it may be the plugs or the coil pack going bad on it,
check plugs doesnt take much for them to get fouled,or wires they are famous for that.IDLE problem dad has 2001 dodge neon check air idle control valve that's fine could it the coil pack?
like the other poster said check the plugs in it those will get some wear on them and cause this to happen,also check and make sure its getting a good fuel supply,any lack of fuel will cause this,id almost bet that it will turn out to be the plugs or a filter clogged up real bad,even a dirty air filter will cause that to happen,good luck.,,PS if it has miss fire in it at lower speeds and on a hard climb it may be the plugs or the coil pack going bad on it,
What is the best form of birth control for someone with mitral valve prolapse?
I have read that oral contraceptives cause blood clots, but what about something like the nuvo ring?What is the best form of birth control for someone with mitral valve prolapse?
You will have to see a cardiologist or gynaecologist or both in order to sort out your problem, web answer can land you from frying pan into the fire.What is the best form of birth control for someone with mitral valve prolapse?
I totally agree with loving_heart. People on here can give you scary advice. Go see your cardiologist and let them know your concerns.
A condom. Or check with your cardiologist.one web hosting
You will have to see a cardiologist or gynaecologist or both in order to sort out your problem, web answer can land you from frying pan into the fire.What is the best form of birth control for someone with mitral valve prolapse?
I totally agree with loving_heart. People on here can give you scary advice. Go see your cardiologist and let them know your concerns.
A condom. Or check with your cardiologist.
How gud is Nissan Sunny N16/new shape, having a constant variable valve timing control(CVTC) type engine?
i wanna buy one asap....Pls tell me if it has good fuel efficiency, anyone?That is my main concernHow gud is Nissan Sunny N16/new shape, having a constant variable valve timing control(CVTC) type engine?
It should have good fuel economy. I would check out http://forums.nicoclub.com for more information.How gud is Nissan Sunny N16/new shape, having a constant variable valve timing control(CVTC) type engine?
It is very fuel efficient, especially if you dont accelerate hard, and use the overdrive all the time. You will love it, and should be an extremely reliable car. Choose your color, girlfriend :)
It should have good fuel economy. I would check out http://forums.nicoclub.com for more information.How gud is Nissan Sunny N16/new shape, having a constant variable valve timing control(CVTC) type engine?
It is very fuel efficient, especially if you dont accelerate hard, and use the overdrive all the time. You will love it, and should be an extremely reliable car. Choose your color, girlfriend :)
Why control valve is always greater or equal to the half of the pipe line size?
Because if the valve is smaller it would restrict the flow.Why control valve is always greater or equal to the half of the pipe line size?
So that there is no appreciable pressure drop in it.
So that there is no appreciable pressure drop in it.
Where is the heater control valve located on a 1998 chevy blazer?
It doesn't have one. If you aren't getting heat, odds are very good that the heater core is plugged. Very notorious for that in that model year (1996 and later). Have it back-flushed at a repair shop.Where is the heater control valve located on a 1998 chevy blazer?
it dose not have
one. the heat is control by
the blind door and mod.
it dose not have
one. the heat is control by
the blind door and mod.
What control meters the ice maker valve?
I have a Kenmore Elite Refrigerator, Model 253.44302400. The ice maker appears to be adding too much water to the mold. The water freezes to the bottom of the ejector and stalls when it rotates and strikes the ice stripper. What control meters the valve to the ice maker?What control meters the ice maker valve?
I do not have the specific details for your unit, but the general procedure, is to control the water valve via the timer. The size of the cubes(which is the timeing of the valve) is regulated via a knob/screw that shows ';';small to large cubes';';, on the face of the ice-maker
I do not have the specific details for your unit, but the general procedure, is to control the water valve via the timer. The size of the cubes(which is the timeing of the valve) is regulated via a knob/screw that shows ';';small to large cubes';';, on the face of the ice-maker
Where is the heater control valve located on a 1973 corvette?
good question i had a 73 vette, I think its under the dash on the passenger side I do know 1 thing for sure they dont have good heaters in them they are not cold weather carsone web hosting
Where is the heater control valve in a 96 lincoln town car?
If you locate the two hoses coming from the fire wall on passengers side where heater is located and follow them you will find he valve at some point.Where is the heater control valve in a 96 lincoln town car?
0 zero, none
0 zero, none
I have a 1989 ford econovan. where would i find the heater control valve and how do i know if its faulty?
My fans are working. the problem i have found so far is when the engine heats up, both heater hoses remain cold. even right into the heater core. thanksI have a 1989 ford econovan. where would i find the heater control valve and how do i know if its faulty?
the valve should be located on the passenger side of the engine bay just before the hoses go through the firewall. once you find it have some one switch the heat on and if the valve does not move remove it and clean it up because on those older vehicles they usually just get rusted up or the cable running to them gets pulled off or fails
the valve should be located on the passenger side of the engine bay just before the hoses go through the firewall. once you find it have some one switch the heat on and if the valve does not move remove it and clean it up because on those older vehicles they usually just get rusted up or the cable running to them gets pulled off or fails
Have check enegine light 1443 where is the evaporative emission vapor control valve at on a 1998 cobra mustang
usually we find that on those the flow sensor that is in line with the vapor control valve gets clogged and sets the code.
You have to find the Evap canister which if I remember is in the front of this vehicle, and there will be a hose leading to the intake of the engine.. there will be a brass colored valve and a black sensor piece in the line along the way.. that is your problem.
Ford had a fix on some vehicles by having you replace the rubber line, the valve and flow sensor as an assembly with a Ford base part number of 9c987
These were a bear to diagnose 10 years ago but in the 10 years, evap has become easier but usually without a shop of tools however it's almost impossible without throwing the kitchen sink at a problem.Have check enegine light 1443 where is the evaporative emission vapor control valve at on a 1998 cobra mustang
a 1443 is a very hard code to get rid of, the evap system controls gas vapors, vapors are not vented to the atmosphere they are kept in the fuel system and burned, there are numerous things that can cause this code and it such a complicated system that joe average will not fix it, ford has test equipment that is needed to fix this - the control valve probably isnt the problem, it can be a pinhole in a vapor line, a bad gascap, see the evap system draws a vacuum on the fuel system, if it cant achive a certain vacuum it sets the 1443 code, i think u will be further ahead to take it to a dealer or ignore the lite, the test equipment needed is so high dollar equipment to buy its not worth your time, i was a ford certified tech and have fought this code many times and they are a nightmare, its a simple system but its very complicated in how it works, someone over engineered this system and its a hard code to get rid of, sorry no easy fix for this code, take it to your dealer
You have to find the Evap canister which if I remember is in the front of this vehicle, and there will be a hose leading to the intake of the engine.. there will be a brass colored valve and a black sensor piece in the line along the way.. that is your problem.
Ford had a fix on some vehicles by having you replace the rubber line, the valve and flow sensor as an assembly with a Ford base part number of 9c987
These were a bear to diagnose 10 years ago but in the 10 years, evap has become easier but usually without a shop of tools however it's almost impossible without throwing the kitchen sink at a problem.Have check enegine light 1443 where is the evaporative emission vapor control valve at on a 1998 cobra mustang
a 1443 is a very hard code to get rid of, the evap system controls gas vapors, vapors are not vented to the atmosphere they are kept in the fuel system and burned, there are numerous things that can cause this code and it such a complicated system that joe average will not fix it, ford has test equipment that is needed to fix this - the control valve probably isnt the problem, it can be a pinhole in a vapor line, a bad gascap, see the evap system draws a vacuum on the fuel system, if it cant achive a certain vacuum it sets the 1443 code, i think u will be further ahead to take it to a dealer or ignore the lite, the test equipment needed is so high dollar equipment to buy its not worth your time, i was a ford certified tech and have fought this code many times and they are a nightmare, its a simple system but its very complicated in how it works, someone over engineered this system and its a hard code to get rid of, sorry no easy fix for this code, take it to your dealer
What are the symptoms of a bad idle control valve?
87 volks cabriolet...hard to start but when running..runs roughWhat are the symptoms of a bad idle control valve?
Will tend to stall when cold, especially when putting the car into gear. You'll probably have to keep your foot on the gas to keep it from stalling at idle if ambient is cold.
It will also usually ';hunt'; for an appropriate idle speed while idling, even when warmed up.
As I recall, with just the key on (not engine running) you will feel this thing (with your hand) ';humming';. Further, if this is a 3 wire gizmo, you should be able to find continuity with a meter between the center terminal and each of the two outside terminals of the valve. On the control side, you should get about 10V between the center terminal (positive) and each of the two outside terminals (controlled grounds).
This replaces the old manually adjusted ';air idle valve'; on a carb.
Will tend to stall when cold, especially when putting the car into gear. You'll probably have to keep your foot on the gas to keep it from stalling at idle if ambient is cold.
It will also usually ';hunt'; for an appropriate idle speed while idling, even when warmed up.
As I recall, with just the key on (not engine running) you will feel this thing (with your hand) ';humming';. Further, if this is a 3 wire gizmo, you should be able to find continuity with a meter between the center terminal and each of the two outside terminals of the valve. On the control side, you should get about 10V between the center terminal (positive) and each of the two outside terminals (controlled grounds).
This replaces the old manually adjusted ';air idle valve'; on a carb.
Where is the heater control valve located on my 2001 mitsubishi eclipse?
Well, I cant really help you with your problem but I have a question for you. I'm thinking about buying a 2003 eclipse gt but my dad wants consumer reviews and the only recent ones i can find are from 2002-2004.
What's your opinion of the car and do you recommend it? About how many miles can you get out of it before it starts giving you mechanical problems?
http://answers.yahoo.com/question/index;_ylt=Aukz5nEd6UR6TFVgw04_6YEazKIX;_ylv=3?qid=20091016172541AAu9pwi
Reply to it on there please :)
Thank you!Where is the heater control valve located on my 2001 mitsubishi eclipse?
whats that
What's your opinion of the car and do you recommend it? About how many miles can you get out of it before it starts giving you mechanical problems?
http://answers.yahoo.com/question/index;_ylt=Aukz5nEd6UR6TFVgw04_6YEazKIX;_ylv=3?qid=20091016172541AAu9pwi
Reply to it on there please :)
Thank you!Where is the heater control valve located on my 2001 mitsubishi eclipse?
whats that
What is a lock up control solenoid valve on an auto transmission?
its part of what shifts the tranny into gear softlyone web hosting
Where is the IDLE AIR CONTROL VALVE located on a 1991 mitsubishi galant?
Under the throttle body where the air cleaner tube clamps on.
How to calibrate a digital control valve in offline having foundation fieldbus ?
hi friends
i want to know about the calibration technque of foundation fieldbus based control valve by a analog sourceHow to calibrate a digital control valve in offline having foundation fieldbus ?
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United States Patent 5431182
Smart valve positioner
US Patent Issued on July 11, 1995
Inventor(s)
Gregory C. Brown
Assignee
Rosemount, Inc.
Application
No. 230492 filed on 1994-04-20
Current US Class
137/85 , With counter-balancing pressure feedback to the modulating device 137/487.5 Electrically actuated valve
Field of Search
137/487.5 , Electrically actuated valve 137/85 With counter-balancing pressure feedback to the modulating device
Examiners
Primary: Gerald A Michalsky
Attorney, Agent or Firm
Westman, Champlin %26amp; Kelly
US Patent References
4712173
Multicontrol process control system
Issued on: December 8, 1987
Inventor: Fujiwara, et al.
Abstract Claims Description Full Text
Description
BACKGROUND OF THE INVENTION
The present invention relates to a valve positioner for controlling a valve which affects a process variable. More specifically, the present invention relates to a valve positioner having a microprocessor.
Various types of positioners are used in the process control industry. Some positioners are mechanically coupled to an actuator while some incorporate the positioner within the actuator. The actuator provides means for physically positioning the valve and may be electric, hydraulic or pneumatic. Electric actuators have a current signal which drives a motor which positions the valve. Hydraulic actuators have oil-filled means for positioning the valve. By far the most common in the process control industry, a pneumatic actuator has a piston or a combination of a spring and diaphragm which position the valve. Depending on the application and the level of control integration, positioners receive several types of input from a controller which are representative of the desired valve position. One type is a current input having a 4-20 mA or a 10-50 mA magnitude, a second is a digital signal superimposed on the current signal and a third is a fully digital input such as Fieldbus or Hodbus.RTM.. Alternatively, the positioner may receive a 3-15 or 6-30 pound per square inch (PSI) pneumatic input representative of the desired valve position. Depending on the level of integration and the application as well, positioners have different types of outputs. Some positioners provide an output current to an electric actuator motor, while still others have a fast responding hydraulic output. The most common type of positioner output is a 0-200 PSI pneumatic output. Positioner, as the word is used in this application, includes all these field mounted instruments, including the various inputs and outputs, and their respective means for positioning valves, if applicable. U.S. Pat. Nos. 4,665,938 and 5,197,328 are examples of valve positioners.
In the most common case of a spring and diaphragm actuator, the diaphragm deflects with the pressure delivered by the positioner, thereby exerting a force or torque on a control valve stem or rotary member, respectively, so as to change the position of the valve. Many positioners have a mechanical or an electronic position sensor to provide a position signal which is fed back into a microprocessor-based control section of the positioner. No matter what the specific means are for delivering force to position a valve, positioners having microprocessors are known. Existing microprocessor-based positioners provide good loop dynamic response, but have a limited band-width so that their usage is limited to slow control loops such as one which controls level in a tank or temperature in a reactor.
With the introduction of microprocessors into valve positioners, the microprocessor is being called on to perform increasingly complex functions, resulting in higher overall power requirements for the positioner. In control systems using, for example, the 4-20 mA, 10-50 mA, Fieldbus and Modbus.RTM. protocols, the operating power of the positioner is limited, since the positioner operates exclusively on the power supplied by the control loop. This limitation has placed an upper limit on the amount of computation and the clock frequency (dynamic response) of the microprocessor in the valve positioner. As technology has advanced, it has been possible to obtain more computational power from a microprocessor without increasing the electrical power requirements. However, the desire to increase control and performance of valve positioners has outpaced the ability of the microprocessor to deliver the requirements under the aforementioned electrical power constraints. A low Dower positioner with wide bandwidths under computer control is needed.
SUMMARY OF THE INVENTION
A valve positioner assembly includes a valve positioner which provides a control pressure to a pneumatic actuator operably coupled to a valve. The valve positioner has an interface coupled to a process control loop for receiving a desired valve position and an analog FID controller which generates a command output for controlling the value, based upon the desired valve position which and a sensed valve position. A microprocessor calculates PID constants, each of which control a variable impedance in the analog PID controller. The digital control signal is stored in a latch and is periodically updated by the microprocessor. In one embodiment, first and second power supplies provide power to the positioner as received over the control loop. The supplies are connected in series.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a control loop including a valve positioner in accordance with the invention.
FIG. 2 is a block diagram of the valve positioner of FIG. 1.
FIG. 3 is a block diagram of control circuitry of FIG. 2.
FIG. 4 is a simplified electrical schematic diagram of a PID controller of FIG. 3.
FIG. 5 is a simplified electrical schematic diagram of power supply circuitry used to power the valve positioner of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a process control loop generally at 10 which typically includes two-wire transmitter 12 which senses a process variable representative of process 14, a controller 16 which may reside in a control room 18 and receives the sensed process variable from transmitter 12 and valve positioner assembly 20 which receives a desired valve setpoint from controller 16 and which controls a physical variable in process 14. Transmitter 12 provides the sensed process variable over a first two-wire circuit formed by cabling 22a and 22b, and controller 16 communicates with positioner assembly 20 over loop 24a and 24b.
A valve positioner circuit 26 in positioner assembly 20 receives a 4-20 mA current representative of the desired valve position, and provides a 3-15 psi pneumatic output 28 to pneumatic actuator 30. Actuator 30 controls valve 32 which controls a flow in process 14. Actuator 30 provides pressure and position feedback 34 to positioner 26.
In FIG. 2, positioner 26 includes communications interface 40 for receiving a 4-20 mA current signal representative of the desired position of valve 32 from controller 16 over wires or a digital setpoint 24a/24b. Interface 40 also provides power supply outputs VS1 and VS2 generated from loop 24a/24b. Circuit 24a/24b can also be a three or four wire circuit as used in the process control industry. Pneumatic output 28 of positioner 26 is connected to valve 32 through actuator 30 so that the applied pressure deflects diaphragm 42 which exerts a force on spring 44 and moves stem 46 within valve 32. Plug 48 mates with stem 46 to slidably obstruct a passageway in valve 32 and control the flow of fluid in pipe 50. Other types of valves, such as rotary valves, may also be used.
Microprocessor 52, which is clocked by oscillator 56, includes on-chip program and storage memory 54 and is preferably made in a low power technology such as CMOS. Microprocessor 52 is connected to a latch and decode circuit 58 and analog-to-digital converter (A/D) 60. Analog-to-digital converter 60 couples to multiplexer MUX 62.
Sum-node circuit 64 is coupled to interface/power supply 40 and receives a signal representative of the desired valve position from interface 40. Sum-node 64 receives three signals from latch and decode circuitry 58: span, zero and input roll/off control. Sum-node 64 provides a position request signal to controller 66.
Control circuit 66 receives four digital control constants from latch and decode circuit 58 representative of the proportional gain signal P), the integral (I), and the derivative (D), along with a position request adjustment signal. The PID control equation which analog circuit 66 implements is given by: ##EQU1## where e(t) is the difference between the desired valve position and the current valve position, t is time, Co is the desired control (command) Output.
Control circuit 66 also receives feedback 34 from position and actuator pressure feedback circuitry 68 and 76. Control circuit 66 provides a control signal to driver circuitry 70 which also receives a pneumatic slew rate control input from circuitry 58. I/P transducer 78 (which includes a booster stage) regulates pressurized air from pneumatic source 80 as a function of the coil drive voltage signal.
Position sensor 82 is coupled to valve stem 46 and temperature sensor 84 is positioned proximate to valve stem 46. Signals from sensors 82 and 84 are provided to multiplexer 62 through position interface 86 and temperature interface 88, respectively. Circuit 68 outputs a temperature compensated position signal to control circuit 66. Actuator pressure interface 76 receives a feedback signal 34 from pressure sensor 90, which measures the pressure in pressure line 28 and provides an input to multiplexer 62 and feedback to control circuit 66. Microprocessor 52 periodically samples the inputs to MUX 62 through A/D converter 60.
There is a continuing need to improve the accuracy with which control valves are positioned. Existing valve positioning devices with a microprocessor allow improved control valve positioning. Additionally, the microprocessor can be used to monitor performance and diagnostics of the control valve. The benefits of an electronic microprocessor-based positioner are extensive and provide many advantages in controlling operation of a valve.
In the present invention, power reduction is achieved by incorporating analog circuitry controlled by microprocessor 52. The analog circuitry performs some of the computationally intensive functions (notably the PID control equation) otherwise performed by microprocessor 52, thus allowing microprocessor 52 to perform other functions without sacrificing control system band width. Thus, the invention provides low power PID control at high speed and wide band-width.
Microprocessor 52 periodically updates the constants of the PID equation. In one embodiment, there are four cases which affect the update rate: calibration, startup, steady state operation, and response to transients. During startup, an initial set of constants is chosen based on, for example, past startups or predetermined values. During steady state operation, the constants are infrequently updated but with a high level of accuracy and control. When responding to abrupt changes, the constants are frequently updated. Typically, when the constants need frequent updating, their accuracy is less important thus allowing faster processing. For example, updates may occur every 0.1 to 0.25 seconds. As the values get closer to their final value, the updating may be less frequent allowing microprocessor 52 greater time for higher accuracy.
Analog circuitry includes sum-node/span and zero adjustment circuitry 64, control block 66, position feedback circuitry 68, driver circuitry 70 and diagnostic circuitry 72. The control equation implemented in the analog circuitry is determined by microprocessor 52 which provides digital control signals to the circuitry. Circuit 66 outputs a command output according to Equation 1.
FIG. 3 is a simplified schematic diagram showing a portion of control circuit 66. Circuit 66 includes sum-node 100, PID circuitry 102 and variable gain circuitry 104. Sum-node 100 receives a representation of a desired valve position from circuitry 64, an adjustment input from latch and decode circuitry 58 which allows microprocessor 52 to adjust the request, and a position feedback signal from circuitry 68. Node 100 sums these signals and provides them to PID circuitry 102. PID circuitry 102 receives the latched P, I and D digital control signals from circuitry 58 and provides a control signal output to variable gain circuitry 104. Gain of circuitry 104 is controlled by a pressure feedback output from pressure feedback circuitry 76 and provides a control signal output to driver 70.
FIG. 4 is a simplified schematic diagram of PID circuit 102 in accordance with the present invention. PID circuitry 102 includes operational amplifier 110, analog switch 112, analog switch 114 and analog switch 116. Switches 112-116, respectively, control the P, I and D constants of circuit 102. The inverting input of OPAMP 110 connects to resistor 118 which connects to node 100 through resistor 120. The non-inverting input to OPAMP 110 is coupled to signal ground and the output couples to driver 70. Analog switch 112 is connected in series with capacitor 122 across resistor 120. Analog switches 112-116 include resistors R1 -R8 and field effect transistors Q1 -Q8. Switch 116 controls P, switch 114 and capacitor 123 control I and switch 112 and capacitor 122 control D.
The gates of FETs Q1 -Q8 are coupled to circuits 58a, 58b and 58c of latch and decode circuitry 58 shown in FIG. 2. Latch and decode circuitry 58a, 58b and 58c receives P, I, and D inputs from microprocessor 52. For example, decode 58c receives a digital value to the derivative constant (D) from microprocessor 52. Decode and latch circuit 58c decodes this value into a combination of analog voltage signals provided to the gates of transistors Q1 -Q8, thereby selectively controlling whether each of transistors Q1 -Q8 is either on or off. Decoder and latch circuitry 58c latches this data following the decoding step so that microprocessor 52 does not continuously supply digital control signals to decoder 58c. Based upon the combination of transistors Q1 -Q8 turned on, the resistance provided by analog switch 112 is controlled to determine the derivative constant of PID circuit 102. Decoders 58a and 58b work in a similar manner whereby the proportional (P) and integral (I) constants are output by microprocessor 52 and selectively modify resistances 114 and 116, respectively.
Valve positioner 20 operates using a hybrid of digital and analog circuitry and thereby achieves advantages of both types of circuitry. Analog circuity performs much of the control which requires high speed and wide band-width so that microprocessor 52 operates with reduced power. However, microprocessor 52 controls operation of analog circuity through latch and decode 58 such that control of valve 32 is not sacrificed. Referring to FIG. 2, microprocessor 52 receives a desired position request from two-wire control loop 24a/24b and feedback from analog-to-digital converter 60. Based upon these inputs, microprocessor 52 configures the analog circuitry by supplying the digital control constants to latch and decode circuitry 56. FIG. 4 is an example of PID circuitry 102 which operates under control of microprocessor 52. Microprocessor 52 also controls sum node/zero and span circuity 64, the slew rate of actuator drive 70, and position request adjustment to circuit 66 of FIG. 3. Although the specific example shows adjustment of a resistance value through switches 112-116, other analog parameters can be adjusted by microprocessor 52 such as current, inductance, capacitance, etc., using similar circuitry in accordance with the invention. Standard circuits in most engineering applications handbooks can be controlled using the present techniques. For example, a voltage controlled gain circuit is controlled by providing a voltage output from A/D converter 60 to the circuit voltage input.
FIG. 5 is a simplified diagram of valve positioner 26 showing a power supply connection in accordance with the present invention. Positioner 26 is shown receiving all electrical power through loop 24a/24b, and does not require an additional power source. FIG. 5 shows interface 40 which includes input/output circuity 140, a 4 volt power supply 142 and a 9.5 volt power supply 144 connected in series with two-wire loop 24a/24b. Four volt power supply 142 provides voltage VS1 for operation of microprocessor 52 and other digital circuitry. Supply 144 provides VS2, a 9.5 volt regulated power supply for analog circuity. I/O circuitry 140 receives the desired position signal over loop 24a/24b in accordance with techniques known in the process control industry. In the embodiment shown in FIG. 5, decode circuitry 58 and sensor interface circuitry are powered by 9.5 volt power supply 144. The circuitry of FIG. 5 shows ';stacked'; power supplies which use almost the entire 15 volt maximum allowed between wires 24a and 24b. If the stacked power supply shown in FIG. 5 is employed, level shifting circuitry (not shown) is necessary to shift levels of various signals.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, actuators other than pneumatic based actuators may be employed, and decode circuitry 58 may comprise a ROM.
* * * * *
Quotables
';I hate what they've done to my child...I would never let my own children watch it. ';
Vladimir Zworykin, television pioneer; Talking about an invention in which he played a critical role.
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i want to know about the calibration technque of foundation fieldbus based control valve by a analog sourceHow to calibrate a digital control valve in offline having foundation fieldbus ?
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United States Patent 5431182
Smart valve positioner
US Patent Issued on July 11, 1995
Inventor(s)
Gregory C. Brown
Assignee
Rosemount, Inc.
Application
No. 230492 filed on 1994-04-20
Current US Class
137/85 , With counter-balancing pressure feedback to the modulating device 137/487.5 Electrically actuated valve
Field of Search
137/487.5 , Electrically actuated valve 137/85 With counter-balancing pressure feedback to the modulating device
Examiners
Primary: Gerald A Michalsky
Attorney, Agent or Firm
Westman, Champlin %26amp; Kelly
US Patent References
4712173
Multicontrol process control system
Issued on: December 8, 1987
Inventor: Fujiwara, et al.
Abstract Claims Description Full Text
Description
BACKGROUND OF THE INVENTION
The present invention relates to a valve positioner for controlling a valve which affects a process variable. More specifically, the present invention relates to a valve positioner having a microprocessor.
Various types of positioners are used in the process control industry. Some positioners are mechanically coupled to an actuator while some incorporate the positioner within the actuator. The actuator provides means for physically positioning the valve and may be electric, hydraulic or pneumatic. Electric actuators have a current signal which drives a motor which positions the valve. Hydraulic actuators have oil-filled means for positioning the valve. By far the most common in the process control industry, a pneumatic actuator has a piston or a combination of a spring and diaphragm which position the valve. Depending on the application and the level of control integration, positioners receive several types of input from a controller which are representative of the desired valve position. One type is a current input having a 4-20 mA or a 10-50 mA magnitude, a second is a digital signal superimposed on the current signal and a third is a fully digital input such as Fieldbus or Hodbus.RTM.. Alternatively, the positioner may receive a 3-15 or 6-30 pound per square inch (PSI) pneumatic input representative of the desired valve position. Depending on the level of integration and the application as well, positioners have different types of outputs. Some positioners provide an output current to an electric actuator motor, while still others have a fast responding hydraulic output. The most common type of positioner output is a 0-200 PSI pneumatic output. Positioner, as the word is used in this application, includes all these field mounted instruments, including the various inputs and outputs, and their respective means for positioning valves, if applicable. U.S. Pat. Nos. 4,665,938 and 5,197,328 are examples of valve positioners.
In the most common case of a spring and diaphragm actuator, the diaphragm deflects with the pressure delivered by the positioner, thereby exerting a force or torque on a control valve stem or rotary member, respectively, so as to change the position of the valve. Many positioners have a mechanical or an electronic position sensor to provide a position signal which is fed back into a microprocessor-based control section of the positioner. No matter what the specific means are for delivering force to position a valve, positioners having microprocessors are known. Existing microprocessor-based positioners provide good loop dynamic response, but have a limited band-width so that their usage is limited to slow control loops such as one which controls level in a tank or temperature in a reactor.
With the introduction of microprocessors into valve positioners, the microprocessor is being called on to perform increasingly complex functions, resulting in higher overall power requirements for the positioner. In control systems using, for example, the 4-20 mA, 10-50 mA, Fieldbus and Modbus.RTM. protocols, the operating power of the positioner is limited, since the positioner operates exclusively on the power supplied by the control loop. This limitation has placed an upper limit on the amount of computation and the clock frequency (dynamic response) of the microprocessor in the valve positioner. As technology has advanced, it has been possible to obtain more computational power from a microprocessor without increasing the electrical power requirements. However, the desire to increase control and performance of valve positioners has outpaced the ability of the microprocessor to deliver the requirements under the aforementioned electrical power constraints. A low Dower positioner with wide bandwidths under computer control is needed.
SUMMARY OF THE INVENTION
A valve positioner assembly includes a valve positioner which provides a control pressure to a pneumatic actuator operably coupled to a valve. The valve positioner has an interface coupled to a process control loop for receiving a desired valve position and an analog FID controller which generates a command output for controlling the value, based upon the desired valve position which and a sensed valve position. A microprocessor calculates PID constants, each of which control a variable impedance in the analog PID controller. The digital control signal is stored in a latch and is periodically updated by the microprocessor. In one embodiment, first and second power supplies provide power to the positioner as received over the control loop. The supplies are connected in series.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a control loop including a valve positioner in accordance with the invention.
FIG. 2 is a block diagram of the valve positioner of FIG. 1.
FIG. 3 is a block diagram of control circuitry of FIG. 2.
FIG. 4 is a simplified electrical schematic diagram of a PID controller of FIG. 3.
FIG. 5 is a simplified electrical schematic diagram of power supply circuitry used to power the valve positioner of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a process control loop generally at 10 which typically includes two-wire transmitter 12 which senses a process variable representative of process 14, a controller 16 which may reside in a control room 18 and receives the sensed process variable from transmitter 12 and valve positioner assembly 20 which receives a desired valve setpoint from controller 16 and which controls a physical variable in process 14. Transmitter 12 provides the sensed process variable over a first two-wire circuit formed by cabling 22a and 22b, and controller 16 communicates with positioner assembly 20 over loop 24a and 24b.
A valve positioner circuit 26 in positioner assembly 20 receives a 4-20 mA current representative of the desired valve position, and provides a 3-15 psi pneumatic output 28 to pneumatic actuator 30. Actuator 30 controls valve 32 which controls a flow in process 14. Actuator 30 provides pressure and position feedback 34 to positioner 26.
In FIG. 2, positioner 26 includes communications interface 40 for receiving a 4-20 mA current signal representative of the desired position of valve 32 from controller 16 over wires or a digital setpoint 24a/24b. Interface 40 also provides power supply outputs VS1 and VS2 generated from loop 24a/24b. Circuit 24a/24b can also be a three or four wire circuit as used in the process control industry. Pneumatic output 28 of positioner 26 is connected to valve 32 through actuator 30 so that the applied pressure deflects diaphragm 42 which exerts a force on spring 44 and moves stem 46 within valve 32. Plug 48 mates with stem 46 to slidably obstruct a passageway in valve 32 and control the flow of fluid in pipe 50. Other types of valves, such as rotary valves, may also be used.
Microprocessor 52, which is clocked by oscillator 56, includes on-chip program and storage memory 54 and is preferably made in a low power technology such as CMOS. Microprocessor 52 is connected to a latch and decode circuit 58 and analog-to-digital converter (A/D) 60. Analog-to-digital converter 60 couples to multiplexer MUX 62.
Sum-node circuit 64 is coupled to interface/power supply 40 and receives a signal representative of the desired valve position from interface 40. Sum-node 64 receives three signals from latch and decode circuitry 58: span, zero and input roll/off control. Sum-node 64 provides a position request signal to controller 66.
Control circuit 66 receives four digital control constants from latch and decode circuit 58 representative of the proportional gain signal P), the integral (I), and the derivative (D), along with a position request adjustment signal. The PID control equation which analog circuit 66 implements is given by: ##EQU1## where e(t) is the difference between the desired valve position and the current valve position, t is time, Co is the desired control (command) Output.
Control circuit 66 also receives feedback 34 from position and actuator pressure feedback circuitry 68 and 76. Control circuit 66 provides a control signal to driver circuitry 70 which also receives a pneumatic slew rate control input from circuitry 58. I/P transducer 78 (which includes a booster stage) regulates pressurized air from pneumatic source 80 as a function of the coil drive voltage signal.
Position sensor 82 is coupled to valve stem 46 and temperature sensor 84 is positioned proximate to valve stem 46. Signals from sensors 82 and 84 are provided to multiplexer 62 through position interface 86 and temperature interface 88, respectively. Circuit 68 outputs a temperature compensated position signal to control circuit 66. Actuator pressure interface 76 receives a feedback signal 34 from pressure sensor 90, which measures the pressure in pressure line 28 and provides an input to multiplexer 62 and feedback to control circuit 66. Microprocessor 52 periodically samples the inputs to MUX 62 through A/D converter 60.
There is a continuing need to improve the accuracy with which control valves are positioned. Existing valve positioning devices with a microprocessor allow improved control valve positioning. Additionally, the microprocessor can be used to monitor performance and diagnostics of the control valve. The benefits of an electronic microprocessor-based positioner are extensive and provide many advantages in controlling operation of a valve.
In the present invention, power reduction is achieved by incorporating analog circuitry controlled by microprocessor 52. The analog circuitry performs some of the computationally intensive functions (notably the PID control equation) otherwise performed by microprocessor 52, thus allowing microprocessor 52 to perform other functions without sacrificing control system band width. Thus, the invention provides low power PID control at high speed and wide band-width.
Microprocessor 52 periodically updates the constants of the PID equation. In one embodiment, there are four cases which affect the update rate: calibration, startup, steady state operation, and response to transients. During startup, an initial set of constants is chosen based on, for example, past startups or predetermined values. During steady state operation, the constants are infrequently updated but with a high level of accuracy and control. When responding to abrupt changes, the constants are frequently updated. Typically, when the constants need frequent updating, their accuracy is less important thus allowing faster processing. For example, updates may occur every 0.1 to 0.25 seconds. As the values get closer to their final value, the updating may be less frequent allowing microprocessor 52 greater time for higher accuracy.
Analog circuitry includes sum-node/span and zero adjustment circuitry 64, control block 66, position feedback circuitry 68, driver circuitry 70 and diagnostic circuitry 72. The control equation implemented in the analog circuitry is determined by microprocessor 52 which provides digital control signals to the circuitry. Circuit 66 outputs a command output according to Equation 1.
FIG. 3 is a simplified schematic diagram showing a portion of control circuit 66. Circuit 66 includes sum-node 100, PID circuitry 102 and variable gain circuitry 104. Sum-node 100 receives a representation of a desired valve position from circuitry 64, an adjustment input from latch and decode circuitry 58 which allows microprocessor 52 to adjust the request, and a position feedback signal from circuitry 68. Node 100 sums these signals and provides them to PID circuitry 102. PID circuitry 102 receives the latched P, I and D digital control signals from circuitry 58 and provides a control signal output to variable gain circuitry 104. Gain of circuitry 104 is controlled by a pressure feedback output from pressure feedback circuitry 76 and provides a control signal output to driver 70.
FIG. 4 is a simplified schematic diagram of PID circuit 102 in accordance with the present invention. PID circuitry 102 includes operational amplifier 110, analog switch 112, analog switch 114 and analog switch 116. Switches 112-116, respectively, control the P, I and D constants of circuit 102. The inverting input of OPAMP 110 connects to resistor 118 which connects to node 100 through resistor 120. The non-inverting input to OPAMP 110 is coupled to signal ground and the output couples to driver 70. Analog switch 112 is connected in series with capacitor 122 across resistor 120. Analog switches 112-116 include resistors R1 -R8 and field effect transistors Q1 -Q8. Switch 116 controls P, switch 114 and capacitor 123 control I and switch 112 and capacitor 122 control D.
The gates of FETs Q1 -Q8 are coupled to circuits 58a, 58b and 58c of latch and decode circuitry 58 shown in FIG. 2. Latch and decode circuitry 58a, 58b and 58c receives P, I, and D inputs from microprocessor 52. For example, decode 58c receives a digital value to the derivative constant (D) from microprocessor 52. Decode and latch circuit 58c decodes this value into a combination of analog voltage signals provided to the gates of transistors Q1 -Q8, thereby selectively controlling whether each of transistors Q1 -Q8 is either on or off. Decoder and latch circuitry 58c latches this data following the decoding step so that microprocessor 52 does not continuously supply digital control signals to decoder 58c. Based upon the combination of transistors Q1 -Q8 turned on, the resistance provided by analog switch 112 is controlled to determine the derivative constant of PID circuit 102. Decoders 58a and 58b work in a similar manner whereby the proportional (P) and integral (I) constants are output by microprocessor 52 and selectively modify resistances 114 and 116, respectively.
Valve positioner 20 operates using a hybrid of digital and analog circuitry and thereby achieves advantages of both types of circuitry. Analog circuity performs much of the control which requires high speed and wide band-width so that microprocessor 52 operates with reduced power. However, microprocessor 52 controls operation of analog circuity through latch and decode 58 such that control of valve 32 is not sacrificed. Referring to FIG. 2, microprocessor 52 receives a desired position request from two-wire control loop 24a/24b and feedback from analog-to-digital converter 60. Based upon these inputs, microprocessor 52 configures the analog circuitry by supplying the digital control constants to latch and decode circuitry 56. FIG. 4 is an example of PID circuitry 102 which operates under control of microprocessor 52. Microprocessor 52 also controls sum node/zero and span circuity 64, the slew rate of actuator drive 70, and position request adjustment to circuit 66 of FIG. 3. Although the specific example shows adjustment of a resistance value through switches 112-116, other analog parameters can be adjusted by microprocessor 52 such as current, inductance, capacitance, etc., using similar circuitry in accordance with the invention. Standard circuits in most engineering applications handbooks can be controlled using the present techniques. For example, a voltage controlled gain circuit is controlled by providing a voltage output from A/D converter 60 to the circuit voltage input.
FIG. 5 is a simplified diagram of valve positioner 26 showing a power supply connection in accordance with the present invention. Positioner 26 is shown receiving all electrical power through loop 24a/24b, and does not require an additional power source. FIG. 5 shows interface 40 which includes input/output circuity 140, a 4 volt power supply 142 and a 9.5 volt power supply 144 connected in series with two-wire loop 24a/24b. Four volt power supply 142 provides voltage VS1 for operation of microprocessor 52 and other digital circuitry. Supply 144 provides VS2, a 9.5 volt regulated power supply for analog circuity. I/O circuitry 140 receives the desired position signal over loop 24a/24b in accordance with techniques known in the process control industry. In the embodiment shown in FIG. 5, decode circuitry 58 and sensor interface circuitry are powered by 9.5 volt power supply 144. The circuitry of FIG. 5 shows ';stacked'; power supplies which use almost the entire 15 volt maximum allowed between wires 24a and 24b. If the stacked power supply shown in FIG. 5 is employed, level shifting circuitry (not shown) is necessary to shift levels of various signals.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, actuators other than pneumatic based actuators may be employed, and decode circuitry 58 may comprise a ROM.
* * * * *
Quotables
';I hate what they've done to my child...I would never let my own children watch it. ';
Vladimir Zworykin, television pioneer; Talking about an invention in which he played a critical role.
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