3. Relief Valve Adjustment

3.Relief Valve Adjustment (1)Main relief valve [1]Install an accurate pressure gauge in the entry circuit. [2]Run the pump at its rated rotation rate. [3]Switch the control valve spool and read the pressure gauge at the cylinder stroke end.

[4]Turn the adjuster clockwise until the required pressure is obtained. The pressure rises 17.8 MPa for one rotation of the adjuster. [5]When the specified pressure is reached, restrain the adjuster so that it does not turn, then tighten the lock nut. (Tightening torque: 27.5 - 31.4 N•m) [6]Again raise the pressure and check that it reaches the specified pressure. (2)Overload relief valve

[1]Switch the control valve spool and read the pressure gauge at the cylinder stroke end. [2]Turn the adjuster clockwise until the required pressure is obtained.

The pressure rises 21.2 MPa for one rotation of the adjuster. [3]When the specified pressure is reached, restrain the adjuster so that it does not turn, then tighten the lock nut. (Tightening torque: 27.5 - 31.4 N•m) [4]Again raise the pressure and check that it reaches the specified pressure.

Switch the spool for the actuator with the overload relief valve set pressure higher than the main relief valve set pressure.

If the set pressure is higher than the main relief valve, replace the assembly for a set relief valve without adjusting the overload relief valve.