What Is the Purpose of a Bleed Valve?

Bleed valves are small but integral pieces of fluid transportation and storage equipment that are used to release a precise amount of liquid or gas in a system. Typically, they are found in pipelines, storage tanks, and pumps where pressure tends to build up or leak during regular use. By releasing trapped liquid or gas, bleed valves ensure that pressure surges are controlled or eliminated to prevent damage to the system. Moreover, bleed valves are also regularly used for maintenance and inspection with little disruption to a fluid network. By understanding how these essential devices work, one can ensure the proper installation and use of bleed valves in their fluid system.

What Are Bleed Valves?

A bleed valve is a screw-type valve that allows trapped vapor or liquid to escape from a system. They are typically opened and closed using a threaded bleed screw that may be operated by hand or automated to open and close at regular intervals. Regardless of how it is operated, bleed valves will generally have a very small inlet so that a limited amount of vapor or liquid may be released for small adjustments to the system. For added functionality, bleed valves can also be combined with block valves to create “block and bleed” valves, or “double block bleed valves.”

Block and bleed valves have both a bleed valve and a block valve so that only a precise amount of fluid may be released. Double block bleed valves consist of a combination of two ball valves and a needle valve. As such, they work on a similar principle to block and bleed valves but with an added layer of protection that provides zero leakage so that maintenance and repair can be done very quickly and safely. For this reason, they are also often used in fueling systems where leakage could be potentially disastrous. Double block bleed valves are also used to provide a temporary isolated portion of a fluid line so that material may be injected or released.

How Are Bleed Valves Used?

Liquid bleed valves and air bleed valves are primarily used to maintain the appropriate pressure in a system by regularly releasing trapped fluids. However, they can also be used to discharge fluid for analysis or to calibrate other control systems. Many industrial applications, including piping systems and heavy-duty gas turbines, utilize bleed valves to either perform maintenance, regulate pressure, or inject something into the system. Bleed valves are also used to transfer fluid from one source to another in very small amounts. This transference is often done to isolate and test a sample of the media flowing through a pipeline, pump, or storage container.


Bleed valves are a core part of many fuel lines, air tanks, gas turbine systems, and more because of the functions they offer. By using a bleed valve, you can efficiently maintain proper pressure in a system, remove a small sample of material for analysis, or close a section of pipeline for maintenance, all with little effect on the surrounding equipment. For access to over 2 billion new, used, obsolete, and hard-to-find industrial and aviation equipment such as bleed valves, cable encoders, and more, you can depend on Aviation Purchasing Platform for reliable, convenient support. Our widespread network of suppliers guarantees expedited shipping for all our customers, located domestically and internationally. More than that, we are also well-equipped to handle all your operational requirements, even finding solutions to AOG situations. Start the purchasing process today when you browse our online catalog of components, and experience all that we can do to simplify the procurement process as your strategic  sourcing partner.


March 20, 2023

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