Understanding Control Pressure Valves and how they work in the industry

10 August 2021

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We understand that the world of regulators can be a little confusing. Each type serves a different purpose based on the application. Understanding what a regulator is, how it works, the difference between pressure reduction and pressure regulation will aid you in finding the best product for the job.

Working in the HVAC, combustion, propane, and industrial markets requires tools and equipment that can handle the demands of process complexity in a safe and efficient manner. One area you should never skimp on is that of your gas regulators.

A pressure control valve opens and closes depending on the set point arranged by a specialist. These handy devices work hard to ensure the gas flowing through the lines into the equipment does so at the right pressure. Too much gas pressure can lead to a catastrophic explosion, harming others and destroying property. Conversely, not having enough pressure will render your equipment useless.

What is a Gas Regulator?

Designed in 1835, the regulator’s concept is easy, and its impact has been long-lasting. There are various types of regulators, but their function is the same: to use a valve system to control natural gas or propane pressure or other gas flow.

There are three primary operating components working together to regulate the pressure within the valve. The loading mechanism determines the delivery pressure. Most often, it is a spring. The sensing element, or diaphragm, senses the force against the spring. Finally, the control element accomplishes the reduction of the inlet pressure through to the outlet pressure.

How Does a Gas Regulator Work?

Gas enters the regulator’s chamber, putting pressure on the diaphragm. The diaphragm then moves upward as controlled by the set spring. This allows a specific flow of fuel from the source to the appliance or device. Adjusting the control knob determines the rate of flow and the pressure. Turning clockwise will push the diaphragm down and allow more gas to come into the valve. Turn counter-clockwise to reduce the amount of fuel and pressure.

Why pressure control valve is used

  It can limit the maximum pressure

  Back-pressure can be set

  These valves would send a signal if the set pressure is reached

  It can protect the pump or system from overpressure

  It can unload a pump

  These valves can set pressure at which oil enters a circuit

What are the functions of the pressure control valve?

•  Pressure reduction•  Load holding•  Sequential control•  Limits system pressure•  Controls the pressure in the selected section of the circuit•  Sequence motion•  Actuator sequence control•  Restrained movement control•  Reduced pressure control

Types of Gas Regulators

Low-Pressure Regulators are available in several different configurations and connection sizes. Beside the meter service governor, there are also in line and coaxial type regulators available. A low-pressure cut-off is optional. The regulators are fire safe.

Medium Pressure Regulators are available in a wide range of different nominal pressures, design features and connections. Beside the standard integrated safety shut-off valve (SSV) other safety devices can be chosen as an integrated limited capacity relief valve or a low-pressure cut-off.

At DMS Metering Solutions we stock three versions of Honeywell Gas regulators, Honeywell J48, J78 and J125. Honeywell has developed a range of safety control devices to guarantee the safe control of gas to protect equipment and appliances from excessive variations above and below the designed pressure parameters. They can be used with natural, liquified petroleum and manufactured gases.


The J48 is an industrial low-pressure regulator suitable for a wide range of pressure reduction applications, including such OEM equipment as boiler and burner trains for a variety of gases.


Sizes: 1", 1 1/4", 1 1/2" & 2”, Inlet pressure up to 350 mbar, Outlet pressure 5 – 160 mbar (2" up to 100 mbar), Temperature range -20 to +70 °C, Quick release spring change facility, Sealed outlet pressure adjustment


The J78 range is a compact, accurate and economical regulator. It is suitable for a wide range of commercial and industrial applications such as boiler and burner trains. The J78 offers positive lock up, and is available in several sizes, with a comprehensive range of regulator springs for different requirements.

The J78 range is suitable for inlet pressures up to 350mbar. The regulators may be utilised for domestic meter service applications with inlet pressures up to 75mbar complying with British Gas specifications.


Sizes: 3/4" and 1", Inlet pressure up to 350 mbar, Outlet pressure 2 – 48 mbar, Temperature range -20° C to +70° C, R version with compact design, RS version with threaded vent


The J125 range of regulators are designed for service applications where accurate pressure control is required. Ideal for industrial pressure reducing, metering stations and for district distribution. Inlet pressure range of 70mb - 8.6 bar. The ¾”, 1" and 1½” sizes are available with screwed connections, the 2” size is available with screwed or flanged connections.

The J125 can have a full or limited capacity relief valve. It can be supplied with the Universal Safety Shut-off Assembly (USSA). This provides overpressure and/or under pressure protection. It gives exceptional consistency of operation and an unrivalled insensitivity to nuisance tripping. All units are suitable for natural, liquefied petroleum and manufactured gases.


Sizes: 3/4", 1", 1 1/2" and 2", Inlet pressure up to 8.6 bar, Outlet pressure 5 – 140 mbar (1") 8.8 – 350 mbar (2"), Available with OPSS, UPSS, Full or limited capacity relief valve, Temperature range -20 to +70 °C

DMS Metering Solutions team of experts can help you find the right gas regulator for your application from our extensive inventory to meet your specific needs.

We will give you everything you need, from pricing to literature, to provide you with an accurate quote that will give you a leg up against the competition. We are your one-stop shop for all your gas regulators, meters, valves, and accessories. We have an extensive stock of gas regulators ready to ship within 24-hours of your order.

Call us on 01773 534555 or email us at for all your gas regulators, gas flow meters, and gas valve needs. You can also view our range of Gas Regulators at

Control Pressure Valves

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