In this guide we’ll walk you through everything there is to know about pressure regulators.
From the basics of how it works to step-by-step repairs and troubleshooting, you’ll gain a solid foundation of knowledge on how to operate and maintain Kimray’s pressure regulators.
Use the table of contents to skip to different sections of the learning path.
A back pressure regulator is a type of control valve that holds pressure on production vessels such as separators, treaters, and free water knockouts and releases upstream pressure when a designated set point is reached.
Simply put, back pressure is pressure that is held back. “Back” in this context means against the natural flow of fluid or gas. In oil and gas applications it refers to upstream pressure that is held, or maintained, in a variety of production vessels to provide the right conditions for separation and processing.
The Kimray Back Pressure Regulator was our original valve, and it remains our most popular. Kimray founder Garman O. Kimmell created this product in 1948.
Up to that point, oil and gas producers had to supervise their wells and adjust back pressure by hand to keep production running. Garman’s invention isolated the operation of the valve from the sensing point of the pressure upstream or downstream.
This meant producers could more accurately control their pressure across a variety of flows using the regulator.
Back Pressure regulators come in a variety of options to meet your particular flow conditions. Options include:
Examples of vessels that require back pressure include separators, heater treaters, free water knockouts, dehydration units and compressors.
In order to perform their function appropriately, these vessels must maintain a constant pressure. This allows fluid or gas to process through the vessel and out for sale, further processing, or disposal.
If this pressure is not consistent, the separation and processing of oil, gas, and water would prove much more difficult.
Our original Back Pressure Regulator is the industry standard for holding back pressure of 300 PSI or less. However, if you need to hold back pressure above 300 PSI, you can use our High Pressure Control Valve in this application as well.
The High Pressure Control Valve can be used with a pressure pilot to provide control in pressures up to 4,000 PSI.
A Back Pressure Regulator monitors and controls upstream pressure. It is an integrated valve because the pilot and the valve are one piece. This animation shows the moving parts inside the valve and the flow through the body.
Please note that the amount of movement shown is exaggerated to demonstrate the working concept.
Upstream pressure flows into the valve inlet and travels through the valve body, exiting through the downstream side. With the adjusting screw unthreaded, there is no tension on the pilot assembly to move the valve to a closed position.
Upstream pressure also travels through the tubing, flowing into the pilot and underneath the sensing diaphragm.
The pilot plug upper seat is closed, blocking upstream pressure. The pilot plug lower seat, which is the pressure vent, is open, allowing the valve seat to be in the open position.
When the adjusting screw is tightened and the pilot spring tension is greater than the upstream pressure, it forces the pilot assembly to move down.
This positions the pilot plug to open the upper seat and allows full upstream pressure to now push down on the motor valve diaphragm. The pilot plug movement adjusts the amount of pressure on the diaphragm, repositioning the stem and seat assembly.
The flow through this regulator is from underneath the seat. The upstream flow pushes up on the seat as the gas is pushing down on the motor valve diaphragm. Because the motor valve diaphragm area is twice that of the seat, the regulator can be held in a closed position with equal pressure on both surfaces.
If upstream pressure exceeds the pilot spring tension, which is your set point, it pushes against the pilot spring assembly, closing off the supply side of the pilot plug and unseating the lower seat, which is the pressure vent.
Gas holding the valve closed then vents from the top of the motor valve diaphragm to atmosphere, allowing the valve to open and the upstream pressure regulated.
The regulator will begin controlling upstream pressure as it increases or decreases, maintaining a constant back pressure set point.
With the upstream pressure neither above or below the set point, the pilot assembly assumes a position in which both seats of the pilot plug are closed.
Oil and gas producers use a Pressure Reducing Regulator to maintain a downstream pressure set point. The pilot and the valve come together as one piece, making it a regulator, or “pilot-integrated valve.”
Some may also refer to this regulator as a “pressure control valve” or a “pressure reducer valve.” Unfortunately, some also confuse the Pressure Reducing Regulator with a Back Pressure Regulator.
Producers commonly use a Pressure Reducing Regulator (PR Regulator) as a suction controller on gas compressors.
Producers also use PR Regulators for re-circulation on gas compressors (“recirc valve”) and to supply fuel gas.
A Pressure Reducing Regulator monitors and controls downstream pressure. It is an integrated valve because the pilot and the valve body are one piece.
With the adjusting screw unthreaded, there is no tension on the pilot assembly to move the valve to an open position.
Upstream pressure flows into the inlet and is blocked by the closed seat in the valve body. Upstream pressure also travels through the tubing into a filter housing where debris and trash are caught to prevent malfunction.
The flow continues underneath the pilot plug and fills the cavity of the motor valve diaphragm. This pushes down on the diaphragm, diaphragm plate, stem, and seat, keeping the valve in the closed position. Because the motor valve diaphragm area is twice that of the seat, the regulator can be held in a closed position with equal pressure on both surfaces.
The pilot plug lower seat is closed, blocking upstream pressure. The pilot plug upper seat, which is the pressure vent, is open, allowing diaphragm pressure to vent from underneath the motor valve diaphragm and the valve seat to be in the closed position.
When the adjusting screw is tightened and the pilot spring tension is greater than the downstream pressure, it forces the pilot assembly to move down.
This positions the pilot plug to open the lower seat and allows full upstream pressure to now flow into the cavity of the motor valve diaphragm.
Now the pressures are equalized on both sides of the diaphragm and the upstream pressure can push open the valve seat.
The booster spring aids in the regulator's opening by pushing up on the diaphragm plate, helping raise the valve seat.
The pilot plug movement adjusts the amount of pressure in this cavity, repositioning the stem and seat assembly to control the downstream setpoint. If downstream pressure exceeds the pilot spring tension, which is your set point, it pushes against the pilot spring assembly, closing off the lower seat and unseating the upper seat, which is the pressure vent.
Gas that has been holding the valve open then vents from underneath the motor valve diaphragm to atmosphere, allowing the valve to close and the downstream pressure to be regulated.
With the downstream pressure neither above nor below the set point, the pilot assembly assumes a position in which both seats of the pilot plug are closed. The regulator will maintain and control a constant downstream pressure set point.
In the non-vent model, the flow path to atmosphere is blocked and redirected downstream. You can convert from a standard PR to a non-vent PR by changing just the diaphragm plate.
In the pressure reducing balanced (PRB) model, the diaphragm pressure is communicated to the motor valve diaphragm cavity and to the regulator's pilot housing. There is an extra housing, pivot screw, spacer and a balancing diaphragm that give this regulator a 100:1 set point drift ratio.
If you work in oil and gas production, you're probably familiar with Kimray's industry-standard Back Pressure and Pressure Reducing Regulators.
In this video, Jeff shows you a few pressure regulators you may not know about:
Common Applications: Meter Run, Gas Lift
The Differential Pressure Regulator regulates the pressure across your meter run. This regulator maintains a set differential pressure across the valve seat so the flow is consistent and metered appropriately.
It can also be used to control the injection flow rate in a gas lift application.
Common Application: Compressor Suction Control
The Pressure Reducing Balanced (or PRB) Regulator is the ideal valve for suction control on your compressor.
This regulator consistently controls a set point downstream even if there are large swings in upstream pressure. It features a 100:1 set point drift ratio versus the 8:1 of the standard version.
Common Application: Holding Back Pressure on a Vessel
Our Back Pressure Regulator with Outside Supply is used in applications where wet supply gas is an issue.
This regulator holds back pressure by using an outside source of gas, like an air compressor, so the wet gas does not disrupt the valve's function.
You can also convert your back pressure valve to a liquid back pressure regulator by changing out a few parts. Just make sure your elastomers are compatible with the fluids in your gas.
Common Application: Vapor Recovery Tower
The Back Pressure Vacuum Regulator is an ideal valve for your Vapor Recovery Tower. This regulator can be used to hold pressure on the tower. When the pressure reaches a set point, the back pressure vacuum regulator will open, sending the gas to a vapor recovery unit for compression.
Pressure Regulators Learning Path
Zero-Emission Regulators
