A mechanical device that permits fluid to flow or pressure to act in one direction only. Check valves are used in a variety of oil and gas industry applications as control or safety devices. Check val [..]

A valve that permits flow of liquid through a hose or pipe in one direction but prevents a return flow. Uses include the prevention of backflow on uphill hose lays, loss of prime with centrifugal pump [..]

A check valve is a valve that allows liquids or gases in a pipeline to flow in one direction but closes to prevent flow in the opposite direction. These types of valves are used extensively in the pipeline industry to prevent reverse-flow or back-flow in the event of a pipeline leak or abnormal operating occurrence.

used to provide flow through a pipe in one direction only. When installed between an external filter and the pond, it keeps the dirty water in the filter from flowing back into the pond if power is lost. They are also used to keep an external pump primed if power is lost. Spring type check valves should never be used in a pond installation. AKA: Fo [..]

– A small device allowing water to flow in one direction only. A check valve has a spring that will hold the valve closed, and will not allow water to flow until a preset press [..]

A valve that allows water to stream in one direction and will then close to prevent development of a back-flow.

A valve that allows water to stream in one direction and will then close to prevent development of a back-flow.

A valve designed to permit flow in one direction only.

a spring-loaded ball or piston valve that allows flow only in one direction.

A valve designed to permit flow in one direction only.

A check valve allows air to flow in one direction but not the opposite direction.

A type of backflow preventer installed in a pipe run that allows water to flow in only one direction.

Device to automatically isolate one part of air brake system from another.  A one-way check valve provides free air flow in one direction only.  A two-way check valve permits actuation of the brake sy [..]

A valve that allows fluid flow in one direction, yet stops flow in the opposite direction.

a mechanical device, a valve, that normally allows fluid (liquid or gas) to flow through it in only one direction. Check valves are two-port valves, meaning they have two openings in the body, one for fluid to enter and the other for fluid to leave. There are various types of check valves used in a wide variety of applications. Check valves are oft [..]

A valve that allows flow to occur in one direction only and will close automatically if a reversal of flow occurs.

A valve that allows the flow of water, chemical or air in one direction only.

 A mechanical device in a pipe that permits the flow of water or air in one direction only.

Used to describe a person, it refers to one who does for himself, but not others. None of the goodies get past him.

A device installed on a pipe to only allow flow discharge in one direction.

A special valve with a hinged disk or flap that opens in the direction of normal flow and is forced shut when flows go in the reverse or opposite direction of normal flows. Also see FLAP GATE and TIDE [..]

A valve that allows liquid to flow through a pipe in one direction only thereby keeping dirty

A valve which permits flow in only one direction.

A device that allows fluid or air to flow in only one direction.

Device which permits fluid to flow in only one direction.

A valve designed to permit flow in one direction only.

A device used to permit the unidirectional flow of air within a compressor.

a type of backflow preventer installed on a pipe so that water is allowed to only flow in one direction.

Device which permits fluid flow in one direction.