Pilot Check Valve/ CETOP3
Sandwich type double pilot operated check valves (DPOCV) or sandwich isolator valve are used in hydraulic circuits for leak free closure of A & B ports for long periods of time. These valves are designed as internally piloted-to-open using pressure signal from opposite actuator port. The valves meet the requirement of CETOP 3 mounting interface (ISO4401) and used in vertical stacking assemblies.
The valve allows free flow in direction A1 to A and B1 to B subject to the cracking pressure and in direction A to A1 and B to B1, the oil flow is blocked. However, the valve can be opened using internal pilot line.
The valve finds usage in hydraulic cylinder applications for pressure holding function. During forward operation, the oil flows from A1 to A (free flow) and the pilot line opens the valve in B line thereby allowing oil from rod side to move to tank. In the retraction stroke, the oil flows from B1 to B (free flow) and pilot line opens valve in A line to tank, thereby allowing retraction of cylinder.
When there is no oil flow from A1 to A or B1 to B, the check valves in both A & B lines are seated and the pressure in the cylinder is locked thereby achieving the required functionality.
