What Is the Function of a Hydraulic Check Valve?by Kevin Boone
Check valves are a form of directional valves--they direct the flow of hydraulic fluid through a hydraulic line or hose. Check valves are used where misdirected fluid flow can damage or destroy equipment or cause a safety issue.
How They Work
Hydraulic check valves mechanisms usually consist of a spring, ball and seal; the mechanism activates when the fluid pressure pushes the spring open. When fluid flow is reversed, the force pushes the ball against the seal, preventing the flow of the fluid.
Hydraulic check valves permit fluid to flow one way. They prevent the reverse flow of hydraulic fluid. An arrow on the valve indicates the fluid flow.
Hydraulic check valves can also control the fluid pressure within a hydraulic line. The pressure is regulated by the spring tension in the mechanism.