Jackwin Hydraulics

A Pilot-Operated (PO) Check Valve is a specialized hydraulic valve that acts like a standard one-way check valve but with a "bypass" feature. While a regular check valve always blocks flow in one direction, a PO check valve can be "told" to open and allow flow in that blocked direction by applying a specific pressure signal (the pilot signal).

How It Works

The valve operates based on three primary ports: Inlet (A), Outlet (B), and the Pilot Port (X).

1. Free Flow (A to B): Fluid enters Port A, pushes the internal poppet against a light spring, and flows freely to Port B. This is identical to a standard check valve.

2. Blocked Flow (B to A): Without a pilot signal, fluid trying to go from B to A pushes the poppet tighter against its seat. This creates a leak-free seal, which is why these valves are used to "lock" loads.

3. Piloted Flow (B to A): When pressure is applied to the Pilot Port (X), it pushes a small internal piston. This piston physically forces the poppet off its seat. Now, fluid can flow backwards from B to A.

The Pilot Ratio