![Check Valves](https://hydraulicsonline.com/wp-content/uploads/2019/03/hydraulic-components1500x300.jpg)
A check valve is a hydraulic control valve that allows fluid to flow in one direction, yet prevents back-flow in the opposite 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.