Frequently Asked Questions


Can I use Fairchild products with liquids or hydraulic applications?

Fairchild's P/I Pressure Transmitters may be used for pneumatic or hydraulic applications, which would include many fluids and liquids. For advice on a specific fluid, please contact our Application Engineering group at (800) 334-8422.

While we typically do not recommend our pressure regulators for liquids, many customers have used them successfully. Again, please contact our AE group to discuss your application in detail.

Can model 4500AEI Volume Booster and Model 90 Relay be used with Natural Gas?

Yes, the model 4500AEI Model 90 Relay can be used with Natural Gas


Who is my local Distributor Sales Representative for Fairchild products?

To find your local distributor for Fairchild's products, click on "FIND DISTRIBUTOR" banner on any page of our website. You will use the drop down boxes to select your zip code (if located in the USA), Province (if in Canada) or Country if you are an international visitor to our website. Once you make a selection, you will be provided with contact information for all Fairchild authorized distributors who service your area.


Why would I want a higher precision pneumatic control product?

A higher precision pneumatic control device may also allow you to improve the quality, speed or productivity of your equipment or process by permitting you to operate well within your desired output even at higher speeds, fluctuating supply pressures, fluctuating temperatures, etc. For your desired precision you should consider not only how your system currently operates, but how it may operate under various conditions in the field.

How do I select a Pressure Regulator for my application?

The first consideration would be to select a unit that can accommodate your supply pressure and output pressure range. Additionally, you should pick a model that provides the flow capacity and accuracy needed to regulate the output pressure for your specific application performance criteria. Lastly, you should consider and additional features you may need, such as our Model 63 filter regulator if particulates may be present in the air, or perhaps the Model 66 stainless steel regulator is material compatibility is an issue.

How do I select an I/P Transducer for my application?

With an Electro-Pneumatic Transducer, the primary considerations are supply and output pressure ranges as well as desired accuracy. In addition, however, do you need a 2 wire process control type device or a 4 wire machine control transducer? Most basic transducers have lower flow capacities, but if you like the convenience and performance of having a transducer with an integral booster, a product like our T7900 or T1750 I/P Transducer units may work best. (Otherwise, higher flow can be obtained by plumbing the I/P Transducer output to the signal port of a Volume Booster and using the high flow output of the booster to actuate your device or process.)

Finally, If you have vibration, moisture, or other environmental concerns, that may influence your selection. For example, the Fairchild TXI7850 product is both moisture and vibration resistant. Lastly, you would look at desired configurations and options, such as field presetting, zero or span adjustment or perhaps Intrinsic Safety or Explosion proof construction and accompanying Agency Approval.

Which Volume Booster should I use for my application?

Fairchild's Volume Boosters, also known as pilot operated regulators, are utilized to increase the output flow over what you may obtain with a basic I/P transducer or pressure regulator. To select a Booster, you should determine how much output flow you require for the application (i.e.: to fill a vessel within a certain time period, actuate a cylinder, etc.). Fairchild’s Volume Boosters, such a s our Model 20 or Model 4500, offer high accuracy control, but in some cases, this might result in undesirable oscillation. For those applications, we offer the "I" option, which is a bypass valve that allows you to adjust the damping of the unit while in operation, to dial in exactly the performance you need to optimize your process or equipment.

How do I select a Pneumatic Relay for my application?

For Pneumatic relay applications, the first question is functionality. Do you need a positive bias, negative bias or reversing relay? For example, if you want the output pressure to always be 5 psi [0.3 BAR] higher than a signal pressure, you would select a positive biasing relay such as the Model 15 (or Model 1500 for higher flow requirements). Other versatile relays, such as the adjustable relay or computing relay allow you to incorporate a variable or sophisticated function in a very simple and inexpensive pneumatic system. For on/off open/close functionality, we offer products such as our M90 selector relay or the M24 Snap Acting Relay.

How should I choose the right Pressure Transmitter for my application?

In pressure monitoring or measurement applications, the first criteria are your input pressure (Fairchild's Pressure Transmitters can be used in either hydraulic or pneumatic applications) and what type of electrical output (i.e.: 0-10 VDC or 4-20 mA). Once you've made a basic selection, you would refine your choice based on your desired accuracy, which in this case would be the maximum allowable deviation from a theoretically perfect relationship between input and output, expressed in % of full scale for linearity, repeatability, hysteresis, etc. Lastly, you would look to connection configurations, material considerations, desired options, such as field presetting, zero or span resetting or perhaps Intrinsic Safety or Explosion proof construction and approval.

What Volume Booster should I use with a valve positioner?

A Volume Booster should be selected to have appropriate flow or the correct Cv factor to power the actuation means such that the valve may be opened or closed within the desired response time. If bi-directional valve operation response is important, you should look toward a Booster with high flow in both forward and exhaust modes, such as our Model 20 (Cv of approximately 1), Model 4500 (Cv of approximately 3) or Model 200 XLR (Cv of approximately 18). Otherwise, our Model 200 or Model 2000 Volume Booster may fit the bill.

Fairchild's Volume Boosters, such a s our Model 20 or Model 4500, offer high accuracy control, but in some cases, this might result in undesirable oscillation. For those applications, we offer the "I" option, which is a bypass valve that allows you to adjust the damping of the unit while in operation, to dial in exactly the performance you need to optimize your process or equipment.


What pressures do Fairchild's products handle?

Our standard pressure regulators have capability to handle up to 500 psi [34 BAR] supply (Model 10 Regulator), with a corresponding output of 400 psi [28 BAR] max. Fairchild’s volume boosters and pneumatic relays include models with up to 250 psi [17 BAR] supply capability. Lastly, while our typical Electro-pneumatic transducers handle up to 150 psi [10 BAR] supply pressure, our new T1750 I/P E/P transducer will handle up to 1000 psi [70 BAR] supply and provide pinpoint precision control of output pressures up to 750 psi [50 BAR].


What level of precision do I need for my application?

The precision you choose will determine how accurately you can maintain, control and/or adjust your "set point" output pressure both when initially set and over time.
Precision is typically designated as a percentage of full scale output, as sensitivity or as the ability to maintain set point accuracy, so you can select the product that best suits your current and foreseeable requirements.

What can be done to a Volume booster to eliminate hunting, or damping the sensitivity?

The Model 20, 4500 and 200XLR Boosters are available with an "I" option, which is the adjustable bypass valve. This option would correct the hunting and reduce the model sensitivity by providing a bypass for the control signal to the outlet port. In addition we use smaller 1/2 area diaphragms to reduce sensitivity even more. This allows better tuning capability with the bypass valve.

On a Model 10, if the setpoint is lowered will excess pressure downstream get relieved backwards?

The standard model 10 is a relieving unit. The relief feature will vent excess pressure from the system through the exhaust port in the bonnet to maintain the required set point. The regulator will vent downstream pressure when the set point is lowered.

Bleed is a constant flow of air across a notch in the exhaust seat which exits the regulator through the exhaust port. This bleed keeps the valve off seat, making the regulator more responsive.

How does a VOLUME BOOSTER increase the volume

The Volume Booster is piped to your supply line. It receives a pressure signal into the booster signal port from a transducer, regulator or other control device and uses that signal to control pressure but allows higher output flow becasuse it has larger valves and takes supply from your supply line. It is essentially a pilot operated regulation device.

On a Model 10, 10264. Should bleed come out the vent? The output pressure is 6.5 barg.

Yes, the Model 10 has a slight bleed in its design to improve responsiveness and accuracy. We do offer a low bleed version of the M10, designated by "B" following the basic part number. We also have other no bleed regulators, such as the Model 1000 and 4000. Please contact our applications engineers at (800) 334-8422, if you wish to discuss your application.

Looking for catalogue 25463

You have our Model 25 Relay with a 1-60 psi output range and 3/8" NPT ports. You can find this unit in the "Reversing Relays" section of our "Relays" product. On the home page, click on "RELAYS" and then "Reversing Relays"

Is volume booster classifed as pilot operated device.

Yes, the volume booster would be similar to a pilot operated regulator, where the application would provide a pneumatic input to the signal chamber and that would control the output pressure. The output flow, however, could be as high as your flow from the supply line to the booster.

Can you get a high precison pressure regulator thats digital? one that doesn't require you to turn a nob to get a reading.

We do have a motorized regulator, which would substitute a DC or AC motor in place of the handwheel. This is a lock in last position device that would be easily controlled by a proportional input.

Another option could be an electro-pneumatic pressure transducer. You would provide an input electronic signal, typically using either 4-20 mA or 0-10 VDC to proportionally control the ooutput. Our T6000 or T7800 products would serve this function. By adjusting the input signal, you can control, adjust or maintain the output pressure.
For more information Click Here

Do Fairchild Transducers meet the secondary seal requirement?

Yes, see the CSA Secondary seal approval notice.
For more information Click Here

Please explain the "ratio" of a volume booster

The ratio is the multiplier or divider of signal pressure to output pressure. For example, a 2:1 ratio means output pressure is 1/2 the signal pressure. similarly, a 2:1 ratio would provide outpressure twice the signal pressure. Note, however, the output pressure can never exceed the supply presure to the booster. Often the signal pressure is lower than the supply pressure because a control device (Valve positioner, I/P, etc.) will only handle a lower supply pressure.

Working principle of Volume booster

A volume booster is connected to the supply line and the output plumbing. It receives a pneumatic control signal, however, from another device, such as a transducer, valve positioner or other control means. this pneumatic signal controls the pressure into and out of the booster, while allowiing the booster to flow the maximum volume of the supply line. Boosters may also be referred to as pilot operated regulators, as your control or pilot signal, maintains the pressure control.

What are the installation instructions for IP transducer T6000

IOM sheets can be downloaded from the "Documents" tab of the Fairchild site.
For more information Click Here

What is meant by the tapped exhaust connection in 24 snap acting relay? Does this tapping affect in any way the relay operation/ process?

Tapped exhaust simply means the exhaust port is tapped so you can plumb off the exhaust through an attached piece of piping. This may be desirable if the media is natural gas, for example, or if you would like to have the exhaust vented away from the immediate relay location. This does not affect the operation of the relay.

Working principle of I/P transducer

An I/P transducer uses an electrical signal input, typically 4-20 mA, as the control signal. This signal then energizes the control chamber elements, which increase or restrict the orifices in the unit to provide a proportionate pressure output. Fairchild I/P products use either voice coil, piezi ceramic disc or feed and bleed solenoids as the actuation system to provide the proportional relationship.

Please indicate if the T6000 unit must be calibrated in its installed position?

We calibrate the T6000 at our facility with the unit in an upright, vertical orientation. As this is a voice coil actuation device, if it is oriented horizontally or upside down in the field, the effect of gravity sometimes causes a slight zero shift. If that would occur, the unit could be easily calibrated by turning the "Zero" and "Span" adjustment screws. While this shift does not occur frequently, we would be happy to calibrate your units here in the same orientation as your installation requires. Just let us know.

I have a High Pressure Regulator "Catalog No 4063" Is there a way to repair them when air leaks from them?

Yes, we offer service kits for these products, which include the elastomers, seals, diaphragms, etc., to make this unit perform like new. The service kit for your unit is p/n 19550-2.

Does a new TT7800 needs calibration if it is installed in an upright vertical position?

No, The T7800 series of product has a piezo disc actuation means and it is unaffected by any change in position or orientation.

Does all inlet & outlet of the pneumatic relay section of TT7800 normally have the

Yes, this is simply to provide a rough barrier to contamination.

How long does it take for transducer T7800 to be shipped to Singapore

Depending on your requested method of shipping, the actual transpotration time can be very quick, a day or two. Passing through customs and other Country procedures when it reaches the destination, however, could delay shipment. That delay could vary between a couple days and as long as a couple of weeks.

Do you have calibration instruction document for T8000 P/I transducer?

Yes, see link to instruction sheet. My apologies as for some reason this sheet is taking a very long time (a couple minutes)to download. We'll work on that.
For more information Click Here

Help me find TD850-AB-D-2245.

This unit is a special configuration of pressure transmitter. Please contact our technical services group at for complete details.

How much is the Cv value when the Model 100 pressure regulator is opened completely?

Cv on the M100 regulator in full open mode is approximately 17.

Is the Model 20 Cat. # 20742E still available? If not please advise replacement.

The updated p/n for this is 20842E. This new p/n indicates a minor revision change to the internal components of the product and will not affect your use, mounting, etc. It is available and price is $217.19.

What is response frequency (Hz) of various volume boosters peneumatic

The frequency response of a volume booster is based on many variables such as the signal chamber and system volume as well as the signal pressure and system pressure. As one of the variables change, the frequency response would change as well which makes the information not very useful. Since the frequency response is not a fixed value and varies with each system, this type of information is rarely compiled or published.

Perhaps the best approach here would be to contact our Applications Engineering department at 800-334-8422 or at, to discuss the specifics of the info you need.


All Fairchild Products carry a two year warranty on material and workmanship. Each product is date stamped and warranted for two years from that date.

Can I clean the electronic feedback nozzle

Cleaning of the nozzle, especially in the critical areas where it interfaces with mating actuation elements, is a factory only process due to the specific internal calibration this part receives. Cleaning at Fairchild can be done in cases where contamination has not progressed beyond the point at which the unit is not repairable. If you want Fairchild to inspect and advise whether it is repairable, please contact our application engineering group at (800) 334-8422 (ext 2)

Thank you!


Yes, the M10 can be used for Hydrogen. if you are using a relieving version, you will need to run a tapped exhaust. Materials of construction are compatible with H2.

Could relay valve increase pilot regulator outlet pressure? if inlet pressure is 6 bars, Could it increase it into 8 bars or more than?

No, a relay can not increase pressure beyond what is supplied to the pilot operated device. We do have a ratio booster, however, that can multiply or divide the pressure. For example, if you provide 5 BAR signal pressure in to a 1:2 ratio booster, the output pressure would be 10 BAR. You may wish to contact our application engineering team at (800) 334-8422 Ext 2, to discuss your needs. You can also email us at to provide t5he detailed information.

Are your products all RoHS compliant?

Yes, our I/P transducers are RoHS compliant. These are the only products in our line to which the ROHS specifications are applicable.

Do you supply Repair kit for the Volume boster and Precision Regulator.

Yes. Please advise the part number of the regulator or booster you have in service.

Do you have a distributor in philippines?

Yes, our distributor is Phone:

Fairchild Process Controls-Philippines
530 B Calbayog Street Highway Hills
Mandaluyong City Metro Manila
Ph: 632-532-4623
Fax: 635.535 5442

Repair kit

We offer repair kits for all products. Please indicate the part number of the product you have.

How do Catalog number 25463 works

The 25463 is a Model 25 reversing relay. It will provide an output pressure which will decrease in direct proportion to an increase in the input pressure to the relay.
For more information Click Here

Can I use a volume booster in an open/closed 2 way valve application?

Yes, a Fairchild booster can generally be used in a two way valve application, because our Model 20, 4500, 4800 and 200XLR boosters, which are the primary selections for valcve systems, have equal Cv in both forward and exhaust modes. The final decision as to one or two boosters would dpeend on your system and pneumatic circuit. We are available to review that circuit and assist you if you would like. You can contact application engineering by or (800) 334-8422 Ext 2. Thanks!!

I am looking for regulators that will operate accurately from 0.1 bars to 0.6 bars with a reasonable flow rate, AND can be externally piloted. Do you have anything suitable? Thanks.

Fairchild can offer an externally piloted regulator, which we typically refer to as our volume booster. We have the Model 20 with 6 to 35 SCFM across a 0.1-0.6 Bar range, the Model 4500 with 9 to 80 SCFM across the same range. For higher flow the Model 4900 with 150 to 300 SCFM across the 0.1-0.6 Bar range. To spec out the correct product, we need to know your supply pressure and what level of accuracy you need. Feel free to email ( or call us (800-334-8422) for further assistance.

Where can the shipping weights be found?

We do not currently have a published list of shipping weights. You can obtain the shipping weight for any model or part number by contacting our Customer Service department at or (800) 334-8422

What is the most common application for a P/I transducer???

Automated pressure control function mounted in a control panel for process or machine control.

What is the fuction of volume booster

The Volume Booster is piped to your supply line. It receives a pressure signal into the booster signal port from a transducer, regulator or other control device and uses that signal to control pressure but allows higher output flow becasuse it has larger valves and takes supply from your supply line. It is essentially a pilot operated regulation device.

What is the difference of between 4516ae3 and 4516ae4

Not sure what is referenced here, as we have no 3 and 4 in the P/N after the "AE" designation. The 4536AE or 4546AE would designate either 1:3 or 2:1 ratio, or the 4513AE and 4514AE would designate 3/8 or 1/2" ports. Those would be the only "3" and "4" designators in the p/n. Please contact our technical support group at if you need more info.

Where is the 10263 made? Is this a U.S. made item?

The Model 10263 is made in Winston Salem, NC, as are all Fairchild products.

How do I know which Fairchild Selector Relay I need, M90 or M91?

The M90 is a low pressure selector relay, designed to select the lower of two signal pressures. Conversely, the M91 is a high pressure selector designed to select the higher of two signal pressures. Please feel free to email ( or call (800-334-8422) if you need forther assistance.

I have a Model 64A air compressor regulator attached to a 60 gallon vertical compressor, I noticed that above the air hose hook up is a hole that you can see the spring on the inside of the unit. The problem is it blows air out this hole, is there a way to fix that from happening or should I replace the unit?

In a relieving regulator, some air will exhaust from the bonnet through the tapped exhaust port. The only issue that would cause excessive air to exit would be a diaphragm rupture or leak. If the diphragm does leak, however, the unit will not regulate pressure. You should replace the unit if it has lost pressure regulation capability.

Pl provide model no 1

Our 1" ported booster would be the Model 4900. See the link below.
For more information Click Here

We are using pressure regulator model (10232JN) for diesel and gesoline application. Have we selected the correct model? If no, please suggest suitable model for fuel applications.

We have a number of customers who use this same model number for diesel or gasoline applications. To really know what product is best for your application, however, we would need to know specifically what the application is, what operating pressures you have, required flows, etc. Please feel free to call [(800) 334-8422], or email us [] for more information.

What is the 'NVG' subfix on Kendal model 10222NVG stand for? Thanks

The N is for non-relieving, the V is for a mounting bracket, and the G stands for gauge.

What is the Cg of pressure regulator model M30?

We do not use Cg as a rating measurement. The Cv range of the model 30 is 0.84 to 1.01.

How do I eliminate hunting with the 4516AE booster

You may wish to use the "I" option 4516AEI product, which has an integral bypass valve. This will allow you to set the gain to tune the booster specifically for your application.

Is there a mounting bracket for the model 4500A volume booster?

Yes. Bracket P/N 20555-1 fits the M4500. Thank you!

We use a lot of T6000-401 I/Ps and we have lousy (oily) air, so we replace them often. Can those be returned for repair or repair exchange? Also, which of your I/Ps is most forgiving of less than ideal air?

Unfortunately, these units usually can not be repaired because the oily substance permiates the internal components. The T6000 is probably the most forgiving because it is a voice coil device and the specific actuation components are not quite as affected as other styles would be, however, oily air will still foul the T6000.

Do you have any failure rate data for your pneumatic snap-acting relays? I am considering using such a relay in an SIS.

The best thing we can supply to you is our warranty return data. Our products carry a two year warranty, so we track returns as a metric of reliability. If this will be helpful, please feel free to send us an email []with the specific model of interest and any other information you need. Thanks!

What are the approvals & certificates for our Model 4100 Low Pressure Pneumatic Regulator? Does it have UL certificate? If not, what kind of equivalent certificates does it have? Thank you.

Fairchild currently does not have UL certification on the M4100. We do, however, have products that have Canadian Registration Numbers and other Agency Approvals. You can view the CRN’s and Agency Approvals for our products on our web site ( under the documents tab (see link provided as well). Other certificates such as conformance, calibration, and origin are available upon request. Please contact the factory at 336-659-3400 for assistance.

For more information Click Here

Why would air leak from the "weep hole" on the side of the booster? Does this indicated a leaking diaphram? I have a Fairchild model 20.

The model 20 is designed as a bleeding style volume booster to increase set point accuracy. The bleed coming from the vent holes do not indicate a leaking diaphragm, but if you feel that any Fairchild product is not working properly please contact the factory at 336-659-3400 to discuss your problem.

Good day! Is there an analogue of the booster 4516E? Necessary to replace the entire booster 4516E. Booster 4516AE is not suitable in size to the existing instrument cabinet. Can you make custom-4516E?

The 4516E is no longer available and has been replaced by the 4516AE. Service kits are available for the 4516E in large quantities. Please contact the factory at 336-659-3400 to discuss any special applications.

What is the failure mode flow rate of a model 10212 regulator assuming 100 psig inlet pressure and atmospheric downstream pressure.

Maximum flow in failure mode would be based on the Cv characteristic of the valve. In this case the maximum Cv is 0.95 which would yield a maximum flow rate of 76scfm at these conditions.

I have two 0 to 2 PSI model 10 regulators. Both units, when hooked to 100 psi line pressure give a blast of 20 to 30 psi pressure before they settle down to the selected pressure. This is not good becuase my 0 to 5regulator i

There could be a couple of problems with your regulator. One problem could be a lack of lubrication on the seal ring causing the output pressure to jump on initial pressurization. If you find that the seal ring is properly lubricated you could reduce the supply pressure to minimize the effect of the pressure spike.

Another problem could be the choice of regulator itself for the application.

Please contact an Applications Engineer at 336-659-3400 to further discuss this application and any problems that you may have with the regulator.

Thank You

May I order Diaphragm Membrane for M10 range 5-300psi


You can order a service kit which includes the diaphragm. It would be p/n 12126-1. List price for the kit is $152.11

How do I order a Supply Valve Assembly for my Model 200XLR?

We have service kits available, depending on which 200XLR configuration you have. Kit part numbers are:

Standard 200XLR kit: 21339-N; 200XLR w/viton kit: 21339-J; Increased sensitivity 200XLR ("L" option)kit: 21339-NL; and 200XLR inc sensitivity w/viton kit: 21339-JL. Please contact customer service ( or your local distributor with the p/n and qty you need for pricing and availability.


Is there STEP or SolidWorks file for a model 10BP available?

yes, we can provide a solidworks drawing. Please email us at or call at (800)334-8422 to provide your complete p/n, email address, etc.

can signal air leak into the supply line in case of booster internal rupture? Booster model 4516A

Signal air can leak into the supply line in the event that both the signal and control diaphragm rupture and the signal pressure is higher than the supply line pressure.

What is the different between 24CC30650400 (we don't have detail specification for this converter) and 24CC3015040?Because the converter 24CC30650400 is obsolete, what is the problem if we replace it with 24CC3015040?The voltage that we used is 110VAC and 50 Hz.

Many years ago we did have other options for the AC motor voltages however these motors are no longer available.

The 24CC30150400 should operate on 115vac/50hz however the speed will be 1/6 slower. Other than this, there should be no problems.

The M10 is said to be H2 rated according to another question in the FAQ; What industry standard is used for the rating of this component? Does it meet HGV 3.1 (Hydrogen Gas Vehicle), NGV 3.1 (Natural Gas Vehicle), or EC 79 (European Commission) industry standards?

The model 10 can be used with hydrogen as the supply media. We currently have customers who do this successfully. The materials of construction are compatible with H2. If you are going to use a non-relieving version, it would be advised to use a tapped exhaust and pipe the vented gas to a safe location.

The model 10 is not rated by any of the industry standards that you have listed. For further information please contact application engineering at or (800) 334-8422 Ext 2.

whether fairchild have adjustable output I/P converter ( Max 10bar output) with very high response (10 hz or better)?

Fairchild currently does not manufacture an adjustable output I/P converter with 10 hz or better response and 10 bar maximum output.

We could offer you the T5200 which has a frequency response of 20 hz but only has an output range of 3-15 psig. You can follow the link below if you would like to take a look at this product.
For more information Click Here

how high precision is achieved in bleed type of pneumatic relays.Explain with sketch.

In a bleed type regulator, such as the model 10, there is a path between the exhaust seat and exhaust pintle that causes a constant bleed. This reduces the amount of pressure needed to unseat the exhaust valve and thus produces a smaller deadband which allows for increased sensitivity of the regulator.

To discuss bleed type regulators or any type of Fairchild product in detail please feel free to call an Applications Engineer at 336-659-3400.

Where to use Bleed type & Non bleed type relay

A bleeding style regulator is typically used when high precision is necessary and the consumption of the supply media is not an issue.

A non-bleeding style regulator is used when the supply media should not be constantly vented due to the cost of the gas, environmental concerns or health and safety concerns.

Most Fairchild products have the option to have a tapped exhaust so the vented gas can be piped away to a desired location.

Please contact an Applications Engineer at 336-659-3400 for concerns or if you require assistance in choosing the correct product for your application.

Thank You!


Fairchild has many regulators that are compatible with nitrogen as the supply media. You could use the model 10 or model 30 for example, if a constant bleed was not an issue. You could use the model 1000 or model 4000 if bleeding is an issue. Choosing the correct regulator would also depend upon the flow capacity desired, the supply pressure, and the set point range.

Please contact an Applications Engineer at 336-659-3400 with any additional questions concerning the use of nitrogen as the supply media for any Fairchild product.

Thank You!

Our booster relay has small air leakage from input signal diaphragm to outside. Can it cause control valve hunting?

If the air is coming out of the exhaust port of the unit it is unlikely that the air is from the signal diaphragm. For example the model 20 volume booster has a built in bleed and will constantly vent a small amount of air.

If the air is found to be normal bleed from the unit and you have control valve hunting it is suggested to use an "I" option unit. For example the I option on a model 20 will call for a by-pass valve. With the by-pass valve you will be able to tune the unit to eliminate osculation and hunting of a control valve.

If it is confirmed that the signal diaphragm is leaking then this could cause control valve hunting. If this is the case a service kit or new unit would need to be ordered and installed.

If you have any additional questions please feel free to contact an applications engineer at 336-659-3400.

Thank You

Volume booster (1:1) is used alongwith positioner (relay with 1:3) for increase in speed of control valve operation by keeping large port openings(Large air volume to fill air actuator).Is it possible only with positioner (output of positioner to be fed directly to control valve) by keeping large port opening, speed of control valve operation can be increased.(i.e both pressure and volume amplification).

It is typically required to have a volume booster to increase the speed of a control valve, this is due to the low flow capacity of a valve positioner alone.

It is not recommended in typical valve control applications to use any ratio other than 1:1 because other ratios can produce instability and problems with tuning.

The link below will send you to a video on how volume boosters work with valve positioners.

For more information or if you have more questions please contact an Applications Engineer at 336-659-3400.

Thank You

For more information Click Here

with reference to previous question of volume booster,why positioner have low flow it posible to increase flow capacity of positioner alone.

A positioner is intended to be used as a pilot device and does not have a high flow output.

You will need a volume booster to increase the flow capacity for a positioner.

If you have any further questions please contact an Applications Engineer at 336-659-3400.

Thank You

Obsoleted date for part number FDJ1032C

This is not a valid Rotork Fairchild part number.

The part number is for a product manufactured by Fairchild Semiconductor with which we have no affiliation.

Thank You

booster bypass

Please follow the link below to find out how the bypass option works on a volume booster and how this option can improve the performance of a valve package system.

Please contact an applications engineer at 336-659-3400 for any additional questions.

Thank You
For more information Click Here

Are the pressure regulators suitable to use with natural and LP gases?

Rotork Fairchild regulators can be used with natural gas as the media.

Please contact an Applications Engineer at 336-659-3400 to discuss any further questions that you may have.

Thank You

Question related to FairChild Model 66 Precision pneumatic regulator. Will the outlet pressure stay same/constant If the inlet pressure changes? For example: At first the Inlet pressure is 1 bar  and outlet 0.4bar. Then the Inlet pressure increase to 3bar, will the outlet pressure stay still 0.4bar? Is there any variation in outlet pressure? Our gauge was showing slightly different pressure every time when we check it. I`m wondering why this is happening. Gauge should be fine.

Any regulator will have some change in outlet with a significant change in inlet pressure. This is known as the supply pressure effect. For the M66, the SPE is less than 0.1 psi[0.007 bar] for a 25 psi [1.7 bar] change in supply. So, with your 2 bar supply increase, the outlet should change no more than 0.008 Bar. if you are seeing more that that increase on the output side, please contact application engineering at (800) 334-8422 ext. 2.

Is air bleed normal on a T7800?

A standard T7800 will have some bleed to maintain the dynamic response capability of the system. The bleed rates are shown on the attached cut sheets. If you feel your product bleeds greater than these very small amounts, please contact application engineering at 336-659-3400 ext 2.

your product Volume Booster were having SIL 3 Certification?

not at this time, however, we have worked with many custyomers to qualify their overall systems as SIL 3 when using our boosters, based on their specific application parameters

What modifiers are needed/recommended to use a Model 10 for natural gas

Model 10 can be used in standard configuration with natural gas. If you have "sourgas" with higher concentration of H2S, however, you'll need the no yellow metals version of the Model 10, designated by a "Y" in the p/n. See table on M10 spec sheet from link below.

For more information Click Here

Positioner is intended to be used as a pilot device and does not have a high flow output.However volume booster is also pilot operated device but have high flow output.Why?

A booster has larger internal chambers and larger valves and it is piped to the supply line. It's job is to reproduce the pressure signal but permit higher flow at that regulated pressure. Thanks,

We are located in SW. PA and need to have a 24XFM repaired where can I send it

we need to have a look at it and assuming no major issues, can repair it at our facility in Winston Salem, NC. Please call our AE group [800-334-8422] for a return number and they can assisst with any further questions.


The regulator I’m using is a Fairchild Model 10233JN pneumatic downstream regulator non-relieving style. I’m using it for gasoline and diesel. I have gotten regulators from you and half of them will regulate just fine at a zero flow rate. Even when left at a zero flow rate the regulators would not increase downstream pressure. But the other half will not regulate at a zero flow rate, when the flow rate is reduced slowly. The ones that are not holding will jump up to the supply pressure. All of the regulators are tested the same way. What can I do to correct the “leaking” regulators so they are all the same?

The model 10 like other Fairchild regulators are tested at the factory using air. The regulator will preform differently when using different types of supply media. We do have a special model 10 that undergoes additional testing to assure proper performance when liquid media is used. To find out more about this special model 10 please contact an Applications Engineer at 336-659-3400 extension 2.

On a Model 10, If the inlet pressure(60psi) is changed to atmosphere, remained pressure(set point 14pis) in outlet should be exhausted.

On a standard relieving model 10 when the supply pressure is removed from the regulator the downstream or outlet pressure will exhaust through the model 10. The downstream pressure will also vent from the regulator if the out put pressure is lowered. For more information and assistance with technical question please call an Applications Engineer at 336-659-3400 extension 2.

Is it always reccomended to connect positioner and booster to the same compressed air supply source ? What is the reason ?

The positioner and booster typically connect to the same supply line for convenience, but it's not an absloute necessity. The booster will provide an output pressure equal to its signal pressure as received and will provide a flow up to either the max flow of the air supply line to the booster or the max flow capacity of the booster. You can not exceed the max flow capacity of a specific booster.


Do your pressure regulators come with a gauge?

a gauge can be purchased as an option on any of our products. See the referenced link and download the spec sheet from the r/h column.

For more information Click Here

what is minimum span? Is it in relation to Supply pressure, or Output pressure ?

Span is typically related to out pressure, as you are adjusting the span of the output. Not sure what product you reference, but in most of our I/P transducers, you can adjust the span by about 1-2 psi on the low end and as much as perhaps 5 psi on the high end. Again, it depends on the model and the initial output range.

Please advice if model:T7900 is still availlable, if not, what is the replacement model?

The model T7900 is no longer available. The model number you would now move to is the T9000 series of products.
The unit in the T9000 series that is the closest match to the older T7900 version is the T9040 unit.
Please follow the link below for more information on the T9000 series of products.
Also please contact an applications engineer at 336-659-3400 if you have any further questions.

Thank You
For more information Click Here

T79xx Series Tranducer Troubleshooting guide

Please contact an applications engineer at 336-659-3400 as the T7900 product is no longer available.

Thank You
For more information Click Here

/P Converter doesn’t generate pneumatic signal \

There are several things that can be checked to insure the I/P is working correctly.
1. Make sure the transducer is receiving the correct and full signal form your controller.
2. Make sure that the proper supply pressure is applied to the I/P.
3. Make sure the unit is piped correctly.

After the above steps if you are still having trouble with your I/P unit please contact an applications engineer at 336-659-3400.

Thank You

TT-6000-41. Should a constant stream of air be coming out of the vent hole?

yes, in some instances air will exhaust through the vent hole. This typically occurs when the downstream pressure would otherwise be higher than the setpoint.


We have SIL 3 ratings on our Model 4500 and Model 4800 boosters designed for valve systems. Contact us if you need further information.



Check the attached link and let us know if you need more assistance.

For more information Click Here

in using Catalog NO. TD6000-406, Is there a problem the device to give more than 20mA input current? What is the output pressure?

This device will accept short term duration currents up to 40 mA, however, the device will try to over range the output pressure, so long term over 20 mA will cause an issue.

How do I find details on Rotork MOV Actuator type CVQ1200F07

Please go to


See attached link and if you still need assistance, please call or email us. (336) 659-3400

For more information Click Here

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