Adjusting Relief Valve - Doosan DX140R Shop Manual

Adjusting Relief Valve

Main Relief Valve (common for body and add-on)
1. This part is designed for non-disassembly and is not
subject to readjustment. If pressure is adjusted, we cannot
guarantee its proper operation.
2. Install a precise pressure gauge at the circuit inlet.
3. Run the pump at the rated rpm.
4. Move the spool in the control valve, read the pressure
gauge indication at the end of the cylinder stroke.
Move the spool of the actuator, for which the set
pressure of the overload relief valve is higher than that
of the main relief valve actuator spool.
5. Turn the adjuster clockwise until the desired pressure is
obtained.
17.8MPa of pressure is increased by a turn of the adjuster.
6. When the desired pressure is reached, and press the
adjuster so that it does not rotate, then tighten the lock nut.
Torque: 27~31N•m
7. Raise the pressure again to check that the specified
pressure is obtained.
Overload Relief Valve
If the set pressure is higher than that of the main relief
valve, it will be activated during the following
adjustment. Therefore, it will not be possible to adjust
the overload relief valve. Do not disassemble or adjust
it. Replace with a complete set of relief valves in
assembly.
1. This part is designed for non-disassembly and should not
be adjusted. Replace by assembly. If the pressure has
been adjusted, we cannot not guarantee its proper
operation.
2. Move the control valve spool, and read the pressure gauge
indication at the end of the cylinder stroke.
Main Control Valve
Page 46
CAUTION
CAUTION
SP001029