Eliminate Fugitive Emissions from your Back Pressure Regulator with this Simple Conversion

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Looking for practical steps to take to achieve your ESG commitments? One source of fugitive gas emissions may be your back pressure regulator.

To eliminate emissions from your regulator, you can either choose a non-vent or an outside supply regulator and tube it to an air compressor. You’ll also see the outside supply regulator categorized as a liquid back pressure regulator.

Either option can be purchased new, or you can easily convert an existing regulator to either operation with only a few extra parts.

If your pressure differential—or the pressure drop across the valve (𝚫P)—is 10 PSI or less, we recommend converting to an outside source of supply air.

For the complete non-vent conversion process, watch this step-by-step video.

Parts List

You will need the following parts and tools to convert a standard back pressure regulator to operate with an outside supply of compressed air.

  • (116*) Diaphragm Plate
  • YAS Filter
  • (262*) Nipple
  • (699) Plug
  • 9/16” wrench / socket
  • Channel Locks (x2 if not using a vise)
  • Loctite
  • Marker (optional)
  • Pick
  • Recommended: Repair kit and grease

*Specific to 2" connection size.

diaphragm plate filter nipple plugparts needed for back pressure to liquid back pressure conversion

Note that anytime you do a conversion like this, we recommend installing a repair kit at the same time. You can watch our step-by-step video for this process as well. In this video, we’ll only be showing the conversion process and not going into a full maintenance repair.

We’re in a controlled environment, but if you are doing this in-line, you will need to isolate and depressurize the valve first.


Step-by-Step Conversion Process


  • First, make a mark down the regulator to help realign the components during reassembly.
  • Unthread the adjustment bolt to relieve the spring pressure.
  • Then remove the pressure gauge.
  • Remove the filter cap and filter screens. This is to eliminate a potential failure point if debris clogs the filter. With this conversion, there is no longer a need for a filter here. We’re only using this to communicate upstream pressure to the pilot.
  • We will be adding a filter to the supply side of the regulator to protect the pilot from any debris in the air line.
  • Once you have removed the filters replace the cap
  • Next, loosen all the tubing connections.
  • Remove the bonnet bolts with a 9/16” wrench, then take off the bonnet, spring, spring plates and spacer ring.
  • Remove the pilot housing and inspect the diaphragm for damage. If it’s damaged, it will need to be replaced.
  • Use a 9/16” socket wrench to remove the (565) pilot seat and pilot plug.
  • Remove the (108) spring and set it aside to be used later.

108 spring

  • Remove and inspect the (1701) diaphragm for damage and replace it if necessary.
  • Use channel locks to remove the diaphragm nut from the diaphragm plate. You could also use a vise instead if you have one available.
  • Remove and inspect the diaphragm and replace it if necessary.
  • Set the diaphragm plate aside - it will be an extra piece. This can also be used to convert other kimray products to non-vent configurations.

diaphragm plate

  • Use the 9/16” socket wrench to remove the (113) pilot seat from the upper housing.
  • Gently remove and inspect the gasket on the pilot seat. Replace the gasket if it’s damaged.

pilot plug upper seat and lower seat



  • Now, put this gasket on the (565) pilot seat.
  • Put the (110) diaphragm on the (113) pilot seat.
  • Take the (565) with the pilot plug by the small ball. Then put the spring in the valve body with the smaller end facing up.

565 pilot seat and pilot plug

  • Thread the (565) down by hand then tighten gently with socket wrench. Be careful not to overtighten because you could damage the gasket.
  • Verify that the pilot plug can move freely and returns with the spring tension before continuing.
  • Put the diaphragm on the new diaphragm plate.
  • Then tighten the diaphragm nut and plate with the channel locks.
  • Use the spacer ring around the diaphragm to know how much to tighten it. If it is too tight, the diaphragm will be distorted and not fit correctly inside of the spacer ring.

spacer ring

  • Place the assembly on top of the pilot housing. While holding it in place, install the (113) pilot seat and (1701) diaphragm into the diaphragm plate.
  • Then gently tighten, being careful not to over-tighten it.
  • Make sure the (1701) diaphragm is centered in the pilot housing.
  • Use the 9/16 socket wrench to remove the breather plug from the upper housing. This will be an extra piece.

remove breather plug

  • Apply Loctite to the (262) nipple (2” specific) and hand thread it into the (YAS) filter.
  • Apply Loctite to the other end of the nipple and hand thread it into the upper housing.
  • Use channel locks on the filter to fully tighten it. The filter cap will point to the downstream side of the valve.
  • Your supplied air to the regulator will come to the bottom port of this filter. It’s important to clear the airline of any debris before hooking it up.
  • Using Loctite, install the gauge into the filter.
  • If you have supply air ready, you can connect it now to the bottom port of the filter to test the seal of the pilot plug. With air pressure to the valve, press down on the pilot plug to clear any debris that might be in the pilot plug area. Feel for any air leaks over the pilot plug. If you can feel an air leak with your hand, the seat may be loose or overtightened, compromising the gasket. There may also be debris on the pilot plug, preventing it from sealing.

debris on pilot plug

  • If the pilot plug is operating correctly, isolate the supply air to the valve before reassembling the rest of the regulator.
  • Re-install the pilot housing on the upper housing, aligning your marks and making sure it’s centered so you don’t pinch the diaphragm.
  • Place the spacer ring around the diaphragm and align it with the bolt holes.
  • Replace the lower spring plate, spring and upper spring plate.
  • Align the bonnet with your markings and hand-start the bolts.
  • Hand-start your tubing connectors.
  • Then fully tighten your bonnet bolts in a crisscross pattern.
  • Now fully tighten the tubing connectors.
  • Using Loctite, thread the new (699) plug into the hole where the gauge used to be.
  • Lastly, tighten your adjustment bolt on top for your desired set point. The instrument air you supply to the regulator needs to be at least 60% of upstream pressure. So if you’re trying to hold 100 PSI, you need at least 60 PSI of supplied air. If you have the ability, just match the supply air pressure with your set point. This will ensure proper operation of the regulator.

We have several solutions available to help you meet your company’s ESG goals, including electric actuators and pilots, non-vent control valves and more.

For more information, check out the website or speak with an expert at your local Kimray store or authorized distributor.