4CKD90 Series Single Pilot Operated Cartridge Check Valve, 25:1 Pilot Ratio, Nitrile Seals

The 25:1 ratio applies specifically to the decompression stage. The main stage runs a 3:1 pilot ratio. That two-stage setup is what lets locked-in pressure bleed down in a controlled way before the main stage opens, which cuts down on the pressure spikes and noise you'd otherwise get from a sudden release.

Built for load holding, a pilot operated check like the 4CKD90 lets oil flow freely toward the cylinder, then blocks reverse flow so the cylinder stays locked when the control valve is centered. When you apply pilot pressure, it unlocks so the load can move again, which is why these are commonly used to prevent movement when the pressure source is inactive.

This 4CKD90 cartridge valve fits a Cavity Size A12336 housing. You'll need to order that separately.