Working Principle
An overcenter valve functions as a combination of a check valve and a pressure control valve. In normal operation, it prevents flow in one direction until pilot pressure is applied from the opposite side, allowing controlled actuator movement. This design is particularly useful in load-holding applications, as it keeps the actuator locked in position when the pump is idle or during pressure loss.
The double version includes two overcenter circuits, one for each actuator line, ensuring safe bidirectional control. The internal pilot lines cross to engage the opposite side’s check valve only when sufficient control pressure is present, ensuring precise motion and preventing collapse or runaway movements.