The Z2S6-40B Type Modular Hydraulic Operated Check Valve is a sandwich plate pilot-operated check valve designed for leak-free shut-off of one or two actuator ports, even during extended periods. It allows free flow in one direction while blocking flow in the opposite direction until pilot pressure is applied. This valve is widely used in hydraulic systems requiring secure load holding, actuator positioning, and leakage-free isolation.

The Z2S6-40B valve conforms to ISO 4401-03 (NG6/CETOP 3) mounting standards and can be easily installed between directional valves and subplates without additional piping.

Working Principle

The Z2S6-40B consists of one or two pilot-operated check valve elements.

Free Flow Direction

Hydraulic oil flows freely from:

• Port A1 → A2
• Port B1 → B2

The check valve opens automatically when flow is in the permitted direction.

Reverse Flow Direction

When oil attempts to flow in the opposite direction:

• The poppet closes against the valve seat.
• Flow is blocked completely.
• The actuator remains securely locked in position.

Pilot Release Function

When pilot pressure is applied from the opposite working line:

• The pilot piston pushes the check poppet open.
• Reverse flow becomes possible.
• The actuator can move in the required direction.

This design provides excellent load-holding capability and prevents unintended actuator movement.

Product Features

• Pilot-operated check valve design
• Sandwich plate construction
• ISO 4401-03 / CETOP 3 mounting pattern
• Reliable load holding function
• Leak-free shut-off in one or both working ports
• Free flow in one direction
• Pilot pressure releases reverse flow
• Compact modular design
• Easy installation and maintenance
• Suitable for vertical and horizontal mounting
• Long service life and stable performance