4CKKT Series Dual Pilot Operated Cartridge Check Valve With Thermal Relief, 4000.00 PSI Pressure Setting, 3:1 Pilot Ratio

Cartridge construction definitely makes this valve suitable for installation in hydraulic integrated circuits, as well as manifold blocks and actuators. It does require a C-10-4 cavity, so make sure that's compatible.

For load holding, a dual pilot operated check valve like the 4CKKT is commonly used to lock and hold a cylinder or other actuator in position. It lets flow go one direction with low pressure drop, then blocks reverse flow until pilot pressure is applied to unlock the circuit.

The pilot ratio is 3:1, and yes, it directly affects your unlocking pressure math. For a single acting cylinder, you need roughly 25% of the locked load pressure in the pilot circuit to release it. Double acting setups are a bit more involved since you have to account for both the blind end and rod end areas, but the 3:1 ratio factors into those calculations the same way. At 4000 psi thermal relief setting, knowing your pilot requirements ahead of time keeps you from undersizing your control circuit.