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4CKKT Series Dual Pilot Operated Cartridge Check Valves With Thermal Relief, Up To 4350 PSI & 6.6 GPM

Description & Features

Application	Pilot check valves allow flow to pass in one direction, with a low pressure drop, then prevent reverse flow until pilot pressure is applied. There are many applications for this valve type, the most common being to lock and hold a cylinder, or another hydraulic actuator, in position. A pilot relief valve will protect the cylinder and hoses from thermal expansion of the hydraulic fluid. See Introduction to Pilot-Operated Check Valves (Lock Valves) at the beginning of this section.
Features	Hardened and ground poppet gives excellent flow capability for valve size, positive sealing and long working life. Cartridge construction allows installation in actuators, manifold blocks and Hydraulic Integrated Circuits. Requires a machined C-10-4 cavity or housing for installation.
Installation	22 ft-lbs torque cartridge into cavity. Unrestricted mounting position. For compatible C-10-4 bodies see
Recommended Filtration	ISO level 18/13 or better.
Specifications	6.6 gpm rated flow. 4350 psi maximum setting. CAUTION: Pressures over 3000 psi require a steel housing. -22° to +194°F operating temperature range. 5 drops per minute max internal leakage between ports 1 and 2. 15 drops per minute max internal leakage between ports 3 and 4. Based on oil temperature of 104°F and 150 SSU.

Products

Model Number	Part Number	Pilot Ratio	Pressure Setting	Pilot Seal	Housing	Seal Material	Price	Action
4CKKT503S328 4CKKT Series Cartridge Valve	401AA00011A	3:1	4000	Standard	None	Nitrile

Product Questions & Answers (1)

Question by: Ronnie J on Nov 29, 2025, 3:54 PM

Is there a certain way this thing needs to be mounted?

Answer by: Customer Support on Dec 1, 2025, 2:07 PM

Mounting position isn't restricted, so you can install it however works best for your setup. Just make sure you torque the cartridge to 22 ft-lbs into the C-10-4 cavity.