Hydraulic pilot operated check valves type Z2S10 are sandwich plate design. They are used for the leakage-free closure of one or two ports, even for long periods of time. Fluid flows freely from A1 to A2 or B1 to B2. Flow in the opposite direction is blocked.
When fluid flows from A 1 to A2, the spool (1) is pressurised and is pushed to the right, thereby opening the ball poppet valve (2) which then opens the check valve (3).
In order to make the reliable closure of the two check valves in the neutral position, the service ports A1 and B1 must be connected to tank.