The short answer to the question, “Can butterfly valves be used with gas?” is: yes! However, not all butterfly valves are suitable for gas—whether it’s natural gas used for home heating or gas used in large industrial plants, butterfly valves have specific types, characteristics, and regulations to ensure they deliver gas safely and efficiently. Let’s analyze butterfly valves and their role in gas systems.
First, let’s discuss the different types of gas butterfly valves. Not all butterfly valves are created equal. They are primarily categorized by how they connect to the pipe and how they seal the gas inside.
A common type is the wafer-type butterfly valve. This butterfly valve is installed between two flanges (the flat, round parts that connect pipes) and uses a rubber seal to prevent gas leaks. It’s inexpensive and takes up little space, making it ideal for small gas systems, such as community gas systems.
Another type is the lug-type butterfly valve. This butterfly valve has small holes on its edge that allow it to be securely bolted to the pipe. The biggest advantage of this butterfly valve is that it can be repaired or replaced without shutting down the entire gas system—a valuable feature for large industrial plants that can’t be shut down. Butterfly valves also differ in their sealing type: “soft-seal” butterfly valves use materials like rubber for sealing (ideal for low-pressure gas), while “metal-seal” butterfly valves use sturdy metal and are used for high-pressure or high-temperature gas, such as that found in oil fields.
So, why do people choose butterfly valves over other valve types for gas transportation? Because butterfly valves have many advantages:
1) Butterfly valves are affordable, both for purchase and installation. Large butterfly valves cost much less than similar-sized gate valves, saving money for cities or companies building gas systems.
2) Butterfly valves are lightweight and compact. Because they are less heavy than other valves, butterfly valves are easier to carry and install in confined spaces, such as under houses or on small factory floors.
3) Butterfly valves operate quickly: They require only a quarter turn (90 degrees) to fully open or close. This means that in the event of a gas leak or emergency, you can quickly shut off the gas with a butterfly valve, helping to keep people safe. Furthermore, with the right butterfly valve, butterfly valves can be used for a wide range of gas types, from natural gas used in stoves to specialized gases used in laboratories. However, using a gas butterfly valve isn’t just about picking a model; you must ensure it’s safe and compliant. Safety is paramount when handling gas, so every gas butterfly valve undergoes rigorous testing. In the US, many butterfly valves adhere to standards set by organizations like the American Petroleum Institute (API) or the American National Standards Institute (ANSI). These standards ensure the valve can withstand gas pressure without leaking. For example, a butterfly valve for low-pressure domestic gas might be rated “PN6” (meaning it can withstand 6 bar), while one used in industrial plants might be rated “PN25” (25 bar).
You’ll also need to check the material: butterfly valves for corrosive gases (such as some industrial gases) need to be made of stainless steel, while those for regular natural gas may be made of cast iron with a protective coating. And don’t forget certifications; some butterfly valves carry labels like “ATEX” (safe for use in explosive areas) or “DVGW” (a European certification also commonly used in the US) to certify their safety.
Let’s take a look at how butterfly valves are used for gas in real life. In residential areas, wafer-type butterfly valves are often used to control the flow of gas to the entire community. If workers need to repair a gas line on a street, they can shut off the butterfly valve in that area without shutting off the gas to the entire town.
In large oil and gas plants, lug-type butterfly valves are widely used because they are easy to maintain; workers can replace a seal or part of the butterfly valve while the rest of the plant continues to operate. Butterfly valves are also used in liquefied natural gas (LNG) facilities, where the gas is kept at extremely low temperatures (-260°F!). These specialized butterfly valves are designed to withstand extremely low temperatures without breaking or leaking. Even in small spaces like restaurant kitchens, small butterfly valves can be used to control the flow of gas to the ovens, ensuring safety in the event of a problem.
Of course, like any tool, gas butterfly valves require proper care to function properly.
Proper installation is key: You must align the butterfly valve correctly with the pipe (there’s usually an arrow on the valve indicating the direction of gas flow) and tighten the bolts evenly to avoid cracking the valve.
You also need to regularly inspect the butterfly valve, checking for leaks around the seals, ensuring smooth movement of the handle or switch, and lubricating components like the valve shaft every few months. If you maintain a butterfly valve properly, it can last for 10 years or more, keeping gas flowing safely.
So, back to the first question: yes, you can absolutely use a butterfly valve to move gas! Whether it’s for a small household system or a large industrial plant, butterfly valves are a safe, affordable, and reliable choice, as long as you choose the right type, follow regulations, and maintain them properly. The next time you turn on a gas stove or feel the heat from a furnace, remember that a butterfly valve is likely working hard behind the scenes to ensure that gas gets where it needs to go safely and efficiently.
