Double overcenter valve

With load restraint, a distinction is made between "locking" and "modulating" a load. If a load needs to be locked in position, a pilot-operated check valve may be a sufficient choice. However, if there is a need to modulate and control a load, an overcenter valve can be a good choice.

The overcenter valve is used to modulate and control the load on an actuator (cylinder or motor). The opening is done via a pilot pressure internal to the valve. In general, lower pilot ratios provide better motion control and stability - especially on resilient systems with high inertial loads

On motors, a high pilot ratio will often provide sufficient dynamic control. A lower opening pressure has the advantage of being more energy efficient, among other things. In addition, hydraulic motors need to be mechanically braked due to internal leakage of the motor.

It is preferable to place the valve as close to the actuator as possible, preferably directly on the actuator with fixed connections. This provides maximum protection in case of hose breaks and the like