Different Types of Gas Shut Off Valves | ValveMan

Whether you're upgrading your residential gas system, looking for the best gas shut off valve for your industrial plant, or simply want to learn more about gas shut off valves, we've got you covered! This guide highlights different types of gas shut off valves, explains how each one works and where they should be used.

Key Takeaways

• Gas shut off valves are essential operational, maintenance and safety devices that control the flow of gas in pipe systems. In addition, they can prevent or limit leaks, acting as a safeguard against hazards such as fires and explosions.
• Different types of gas shut off valves include ball, gate, globe, and plug valves. Each type is suited to specific functions and applications, making it important to choose the right valve based on functional, operational or project-specific requirements.
• Proper installation, maintenance, and understanding of operational and emergency procedures related to gas shut off valves are essential in ensuring efficiency and safety in gas systems.

Understanding Gas Shut Off Valves

There are many types of gas shutoff valves, a simple way to classify them is based on their function.

Appliance or equipment shut-off valves: These gas shutoff valves are located at each appliance, such as an oven, geyser or furnace. These valves allow you to turn off the gas supply to a particular appliance or piece of equipment, which may be required to perform maintenance or in case of an emergency.

Main shut-off valves: This is the primary isolation valve along a gas pipeline, or in gas reticulation systems. In bulk utility applications, these valves are often found near meters, and are used to shut off the gas supply along pipelines, to different regions, or to specific properties.

Automatic shut-off valves: Automatic gas shut-off valves are essentially safety valves, which automatically stop or divert the flow of gas in response to emergency conditions, such as a gas leak, excessive gas flow (indicative of a large pipe break or rupture), or seismic activity. Specific types include:

Seismic valves: These valves incorporate an internal mechanism that reacts to significant tremors, automatically closing the valve and shutting off the gas supply, in order to prevent any leakage.

Excess flow valves: These are typically installed on gas utility service lines, to shut off the gas supply if there is a sudden, substantial increase in flow, typically caused by a line breakage or rupture.

Automated and remote shut-off valves: Modern valves can be controlled remotely and automatically, based on pressure, temperature, leak detection or other sensor feedback. Automatic shut-off valves may also be connected to alarms or warning systems.

Types of Gas Shut Off Valves for Different Applications

It should be clear from the previous section that gas shut off valves are much more than just operation and maintenance valves, they also serve as system control and automation valves, and especially safety valves.

Gas shut off valves are available in many valve types. From quick, simple and effective ball valves, to robust gate valves and reliable plug valves, understanding the different gas valve types will help you choose the best valve for your application.

Ball Valves

Ball valves are known for their simple design, quick operation and excellent sealing capabilities. A quarter-turn of the valve handle can quickly shut off gas flow, making ball valves an ideal choice for situations where rapid response is necessary. Ball valve designs feature a rotating ball element with a hole through the middle, the hole through the ball aligns with the gas flow when the valve is open, and the surface of the ball blocks gas flow when the ball is closed.

The effectiveness of ball valves lies in their ability to provide a leak-tight seal, significantly reducing the risk of gas leakage. This makes them a popular choice in residential, commercial and industrial applications. Have a look at this article if you'd like to know more about gas ball valves in industrial applications.

Gate Valves

Gate valves are often used along bulk gas supply lines due to their full port design, which allows unrestricted flow through the valve when fully open. Gate valves operate by lifting the valve disc (also called the gate) out of the path of the gas flow, providing an unobstructed opening that minimizes flow resistance and pressure drop, allowing for a large flow capacity through the valve.

An advantage of gate valves is their ability to handle high flow rates, making them suitable for main gas supply lines. They should not be used for flow control or throttling purposes, a partially open gate valve experiences a high velocity through the small valve opening, which causes turbulence and accelerates wear of the valve seat.

Globe Valves

Globe valves are essential for applications requiring flow control and regulation. They operate using a disc which moves up and down relative to a stationary valve seat. This allows for precise control over gas flow, by regulating pressure drop across the valve.

Suited to flow control and pressure regulation in gas systems, globe valves may also be used to shut off gas flow completely. However globe valves are relatively bulky, heavy and slow to operate, hence they they are often installed together with ball valves or gate valves, which function as the primary isolation valve, leaving globe valves to fulfill the flow control function.

Butterfly Valves

Butterfly valves are lightweight and generally cost-effective, making them a popular choice for gas flow regulation. These valves are compact, and also available in wafer and lugged designs, which make them particularly advantageous in areas with accessibility and space constraints.

The efficient operation and compact design of butterfly valves, make them worth considering for residential and industrial applications. The ability to quickly regulate gas flow while taking up minimal occupying minimal space is a significant benefit of these valves.

Plug Valves

Plug valves are recognized for their durability and reliability, particularly in high-pressure and high-temperature applications. They control gas flow using a cylindrical or conical plug-shaped element that rotates within the valve body.

These valves are used widely chemical processing facilities due to their ability to withstand harsh conditions and reduce potential gas escape points. Their robust design and range of material options makes them a smart choice in demanding environments such as the oil and gas industry, petrochemical processing and high pressure gas systems.

Specialty Gas Shut Off Valves

In addition to the traditional gas shut off valves discussed above, many gas systems include specialty gas shutoff valves. These include seismic gas shut off valves, excess flow valves, and solenoid valves.

Seismic Gas Shut Off Valves

Seismic gas shut off valves are typically installed in earthquake-prone regions to prevent seismic related gas leaks, fires, or explosions by automatically cutting off the gas supply during earthquake activity. These slam shut valves are mandated in certain residential, commercial and industrial installations, depending on the region and applicable regulations, codes and standards involved.

Seismic shut off valves work using a mechanical or electrical motion-sensing element, that triggers a valve closure once a pre-set seismic or vibration amplitude is reached. Gas flow is shut off until the valve is manually reset.

Excess Flow Valves (EFVs)

Excess flow valves are designed to react to large, sudden increases in gas flow and automatically close, halting the supply of gas and preventing dangerous leaks. While normal gas flow rates do not affect valve operation, excessive flows are strong enough to activate the valve closure mechanism.

The primary application of excess flow valves is in underground gas service lines, residential and commercial gas supply lines. They act as safety valves by preventing significant gas leaks that may be caused by pipe rupture or digging near underground pipelines.

Solenoid Valves: Automated Control

Solenoid valves utilize an electromagnetic mechanism, also known as a solenoid, to control the opening and closing of the valve, providing automatic and reliable gas flow. These valves are commonly employed in industrial systems where remote, automated gas flow control is required.

An added safety benefit of solenoid valves is that they may be supplied a a normally closed (NC) design. This means that the solenoid is used to hold the valve open and allow gas flow while energized, but if it is de-energized, whether intentionally or due to a power trip, the valve will close. This ensures that the gas supply is automatically shut-off in the event of a power failure.

Which Gas Shut Off Valve is Right For You?

Selecting the correct type of gas shut off valve is essential for both safety and system efficiency. Depending on your location and industry, it may also be a legal requirement. Factors to consider include:

• The valve application. For example is your valve being used for appliance or equipment isolation, is it being used in industrial or chemical processing plants, is it being used for utility services or for residential applications.
• Operating pressure, flow and temperature ranges.
• The process media flowing through the valve.
• Ambient conditions and the installation and operating environment.

Metallic gas shut off valves such as stainless steel, cast steel or brass valves are typically chosen for applications involving flammable gases due to their ability to withstand higher temperatures and pressures in comparison to plastic valves. Remember that valve size, actuation and connection details should suit process and piping requirements.

Gas Shut Off Valve Installation, Maintenance and Operation

Proper installation, operation and maintenance of gas shut off valves are essential in ensuring optimal performance, safety and reliability of these valves. Key practices include regular inspections for signs of wear and damage, as well as adequate lubrication to maintain valve functionality.

Gas shut off valves serve as the first line of defense during emergencies like gas leaks, earthquakes, or equipment failures. If you smell gas indoors, evacuate immediately, raise the alarm, and call emergency services as well as your gas supplier, but only once you are in a safe area.

Steps for shutting off gas valves safely during emergencies include assessing the situation, ensuring the environment is safe, and then using the gas shut off valve (if you know how to use it!).

Being prepared and knowing how to perform an emergency gas shutoff can be crucial in emergency scenarios. Before a real-life emergency occurs, it’s crucial to:

• Create an emergency response plan and emergency evacuation plan.
• Learn where the gas supply line and shut-off valve is located.
• Understand the procedure to manually shut off the gas supply.
• Store any special tools, such as wrenches or keys, near the gas valve or gas meter for easy access.
• Ensure that contact numbers for emergency services and your gas supplier are displayed nearby.

Locating and Identifying Your Gas Shut Off Valve

In industrial settings, gas shut off valves may be found anywhere on the plant where gas lines are running, be they along process and product lines, part of the auxiliary service lines, or for equipment isolation.

In gas utility supplies, commercial and residential applications, the main gas shut off valve is usually found just before the gas meter. This is commonly known as the meter valve or street side valve. In most modern buildings a house-side shutoff valve, typically a ball valve or gate valve, is found where the gas pipe enters the home. Each gas appliance should have a dedicated, easily accessible shutoff valve located nearby. The proximity of this valve may be governed by applicable regulations.

In Conclusion

Gas shut off valves are essential components in gas systems including natural gas, liquefied natural gas (LNG), liquefied petroleum gas (LPG), biogas, chemical processing and many others. Gas shut off valves ensure the safe performance of gas-based fluid systems. From ball valves to plug valves, each valve has its advantages and is suited to specific applications, making valve selection critical.

Proper installation, regular maintenance, and being prepared for emergencies are key factors to prevent dangerous leaks and ensuring the safety of your gas systems. Be sure to manage these vital components.

If you’re still not sure which valve is the best for your project, or if you'd like more information about our gas shut off valve product offering, get in touch with the experts at ValveMan. With technical expertise and reliable customer support a hallmark of our 60 year legacy, we’ll definitely be able to guide you to the best valve solution for your needs.

Mark Trainer

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Mark Trainer, a Navy Veteran Aviation Electronics Technician and an authority in the valve industry, brings over 40 years of experience in process valves and controls to his role as an Outside Sales Representative for ValveMan.com and FS Welsford Company. His profound knowledge of valve types and control loops, coupled with his ability to provide strategic solutions, has earned him a reputation for reliability and professionalism. Mark's unwavering commitment to customer service and his ability to navigate complex technical challenges consistently result in successful outcomes, driving growth and delivering outstanding results for both companies.