# Pilot Operated Valve Setup Procedure

A sufficient amount of air is a must to keep the parallel arm in position. Pilot Operated (PO) Check Valve prevents the pneumatic cylinder lift-assist if the air is exhausted. The function of the PO Check Valve is to prevent the parallel arm segment from falling downward in case of a sudden loss of air.

1. Turn on the air supply, set both the filter regulator and precision regulator pressures to properly balance the arm.

2. Lower the arm to the lowest position in its vertical travel or place the arm in the park position to prevent the arm from falling in case of air loss.

3. Decrease the main supply pressure to 0.3 bar (4 psi) less than the required balance pressure.

4. Ensure arm is still in balance and functional.

5. Increase (clockwise) the PO check adjuster to maximum spring pressure.

6. Verify that the PO check valve is now closed, meaning the cylinder will be locked and unable to move.

7. Slowly decrease (counter-clockwise) the pressure on the PO check valve until the valve opens, or until the cylinder is able to move again.

8. Increase the main supply pressure back to nominal specified pressure.

9. If performed properly, the cylinder will now remain in place if the air supply is suddenly lost.

10. Lock the PO check adjuster with the set screw to ensure undesired movement does not occur.