[132] Delockable non-return valve (2)
The released piston is
pressurized via pilot port X. This lifts the sealing element from
its seat and releases flow from B to A.
In order to release the valve reliably, the effective area of the pilot piston must always be greater than the effective area of the sealing element. Piloted non-return valves are also available with lockable non-return function.