How many ports does a double pilot-operated check valve have?

• A. 4
• B. 3
• C. 5
• D. 2

Answer: (A)

Double pilot-operated check valves are built to hold a load in place and only allow flow when commanded by pilot pressure. The core is a check valve in the main line that normally blocks flow in one direction. To control it, there are two small pilot passages that supply pressure to move the valve element off its seat. These pilot circuits are separate from the main flow path, and having two of them means you can actuate the valve from either direction or from two different pilot sources. Therefore the valve body has four ports total: two main-line ports for the hydraulic flow, and two pilot ports that receive the control signal.