How Does a Gas Regulator Work?

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.

Link to ABYDA

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.

Learn the Basics of Gas Regulators to Make Better Decisions

We understand that the world of regulators can be a little confusing. Each type serves a different purpose based on the application. Although you can rely on experts like us to help you out, understanding what a regulator is, how it works, the difference between pressure reduction and pressure regulation, and dual-stage vs. single-stage, will aid you in finding the best product for the job.

Here is a breakdown of what you need to know about gas regulators, whether it&#;s a natural gas regulator or a propane gas regulator.

What is a Gas Regulator?

Designed in , 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.

Common appliances that use regulators include gas stoves, propane grills, or oxy-fuel bottles for welding. Each type of regulator&#;s components consists of a set spring attached to a rod that runs down from a set screw through a diaphragm into the valve.

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.

B38 Series Line and Service Regulator from Itron

The mechanics of the gas regulator work well together. However, there is another component that comes into play called the surrounding air. Atmospheric pressure, based on the elevation above sea level that the building sits, will affect gas pressure. The inner parts work by sensing the pressure both upstream and downstream. The air pressure affects the way the regulator senses downstream pressure.

What is the Difference Between Pressure Reduction and Pressure Regulation?

The application between the two types is the main difference. A pressure reduction regulator is used to reduce the input pressure of the gas, so that it is at the ideal pressure on the outset. It is a normally open valve installed upstream of the pressure-sensitive equipment it needs to regulate, as it controls downstream pressure.

Pressure regulation is often called a back-pressure regulator or back-pressure valve. Its purpose is to maintain a set pressure at the inlet. It is a normally closed valve and is installed in parallel with or just after sensitive equipment to maintain upstream pressure.

See Norgas&#; Selection of Gas regulators

Dual-Stage versus Single-Stage &#; Why Does it Matter?

Dual-stage regulators utilize two regulators within the same housing, which operate to reduce pressure in two steps instead of only one step. At the first stage, the pressure of the supply (inlet) gas is reduced at an intermediate stage, generally about three times the maximum working pressure. The second stage further reduces the pressure to a reasonable working pressure. Sometimes, a dual-stage regulator may have two safety valves to lessen the possibility of an explosion.

Dual-Stage Regulator (Source: Wikipedia &#; author: Mintrick.)

Single-stage regulators only have one regulator in which the gas supply enters, and the pressure is reduced. The delivery pressure is not as controllable as a dual-stage one is; thus, it should be used in operations where it can be monitored and easily adjusted as required, or the source pressure is nearly constant. An example of a single-stage regulator is a line regulator.

Single Stage Regulator (Source: Wikipedia &#; author: Mintrick.)

Choosing which type to use should be based on the required consistency of gas flow needed for operating. Consider what kind of gas flow is required, and then make your choice.

Types of Gas Regulators

The types of regulators are extensive and include appliance, line and service, pilot operated, direct acting, high pressure, back pressure, relief valves, and propane regulators. You can even find specialty items such as high-purity regulators for those unique jobs. At Norgas Controls, you can find the right type of regulator for your specific needs.

Finding The Right Gas Regulator

Norgas&#; team of experts can help you find the right gas regulator for your application from our extensive inventory or design a custom solution to meet your specific needs. We have an extensive inventory of gas regulators ready to ship within 24-hours of your order.

If you want to learn more, please visit our website Propane Tank Gauge Level Indicator.

Need to set up a quote for a client? Contact us. We will give you everything you need, from pricing to literature, to provide your customer 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.

Natural Gas Regulators Are a Critical Safety Device: Here&#;s How They Work

by Bob Shively, Enerdynamics President and Lead Facilitator

The number of accidents on the gas transmission and distribution system are low given the 3 million miles of pipeline in the U.S. But over the last 10 years, gas distribution and transmission systems have caused incidents resulting in an average of 11 fatalities and 48 injuries per year according to the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA). Gas operators strive to continually drive these numbers to zero. A key device in preventing accidents is the gas regulator, which is found throughout the system from the wellhead to the customer meter. Everyone involved in the natural gas business should understand what a regulator is, how it works, and how it is critical for ensuring a safe gas system.  

A regulator is a device used to reduce pressure in the gas delivery system. Regulators are commonly located at the interconnect between the transmission and distribution system, at locations in the distribution system where higher-pressure pipes are connected to lower-pressure pipes, and where the gas enters an end-use consumer premises. Correct operation of regulators is critical to ensure that downstream pressures do not exceed pipe maximum allowable operating pressure (MAOP) while also keeping pressures high enough to reliably serve customers.

The type of regulator used depends on the application. The two most common types are spring-loaded regulators and pilot-operated regulators.

Spring-loaded regulators

A spring-loaded regulator, also called a direct-operated regulator or a diaphragm regulator, is the simplest of the two types. The spring-loaded regulator is a self-contained device that partially opens or closes a valve to control or regulate the flow of gas through the regulator. The position of the valve is automatically adjusted to allow more or less gas to flow depending on the pressure downstream of the regulator. If more gas flows through, downstream pressure will rise. If less gas flows through, downstream pressure will drop.

The spring is set so the force of the spring determines the position of the diaphragm, which in turn controls the lever to determine the valve position. Downstream pressure presses against the bottom of the diaphragm, which is balanced by pressure from an adjustable spring. The opposite reaction will occur if downstream pressure falls below a set point, resulting in the valve opening further to allow more flow, thus increasing pressure. 

If downstream pressure rises beyond the desired set point the extra pressure pushes on the diaphragm, compressing the spring and causing the regulator mechanism to partially close the opening. This reduces flow and returns the downstream pressure to the desired level.  Spring-loaded regulators are typically used for regulating pressure into a customer facility and as part of a more complex regulator called a pilot-operated regulator. The advantage to this type of regulator is that it has few components and is the lowest-cost option. 

Pilot-operated regulators

A pilot-operated regulator is more complex than the spring-operated regulator and provides more precise pressure control of gas flow by continually making small adjustments to downstream pressure. They are more expensive and require more maintenance than spring-loaded regulators. Thus, they are used in situations where the extra expense is justified given the need for precise control for safety or operational efficiency.

These applications include use in transmission pressure limiting stations and in district regulator stations, and for other applications with high flow rates such as power plants and large industrial customers.

The two key components that make up a pilot-operated regulator are a main valve that controls the downstream pressure and a pilot regulator that controls the amount that the main valve is open. By controlling the position of the main valve, the pilot regulator determines the amount of gas flow the main valve lets through, thus controlling the downstream pressure. 

The position of the main valve is determined by the relationship between upstream pressure, the loading pressure, and the downstream pressure. The more the main valve is open, the higher the downstream pressure. Changes in downstream pressure result in a series of reactions that change the position of the main valve. When the downstream pressure changes it changes the position of the pilot regulator. This controls the amount of downstream gas that bleeds into the loading pressure, thus increasing or decreasing the loading pressure. In turn, the change in loading pressure changes the position of the main valve, thus changing the amount of inlet gas that flows through the regulator. If more gas flows through, the downstream pressure will go up. If less gas flows, the downstream pressure will go down. 

How regulators ensure safety

Pipeline pressures that exceed MAOP risk rupturing pipes causing leaks and potential explosions or fires. Regulators are the key component that prevents this. They are installed in configurations to ensure downstream pressures remain at safe levels. In locations where single regulators are installed, they are designed to fail shut, meaning that if the regulator is failing to control downstream pressure it will shut a valve and cut gas flow downstream. This is how the regulator on your house keeps you safe.

     A district regulator station with a parallel run

For more critical regulators that serve many customers, such as regulators at a district regulator station, duplicative regulators are placed in line in a single pipe run. If one regulator fails, a second regulator will take over the job of controlling downstream pressure until a crew is dispatched to address the failure. Often a second parallel run will be installed so that gas flow can be switched to the second line while maintenance is performed. This provides continuous service while safety is ensured. Such critical regulators are checked and maintained regularly to make sure they will continue to operate as designed.