Installation; Operation - Doosan DX140R Shop Manual

3. Turn the adjuster clockwise until the desired pressure is
reached.
21.2MPa of pressure is increased by each turn of the
adjuster.
4. When the specified pressure is reached, press the adjuster
so that it does not rotate, and tighten the lock nut.
Torque: 27~31N.m
5. Raise the pressure again to check the rated pressure has
been obtained.

INSTALLATION

1. Piping should not exert unnecessary force on the valves.
2. Bolts must be tightened uniformly.
3. Welding work near the valves may damage the seals due
to excessive heat or flame.
4. Keep the ports covered until connected with a pipe in order
to prevent dust.

OPERATION

1. Check that the hydraulic circuit and oil are clean before
operation.
2. Oil must be hydraulic oil, with an aniline point of 82~113°C
3. Keep the relief valve below the specified pressure.
4. The pressure difference between the main relief valve and
the overload relief valve should be set at a minimum of
2.0MPa.
5. Perform deaeration and warming up before operation.
• In particular, when the temperatures of the hydraulic
oil and valve are low, observe the following
instructions in order to prevent the stick of the spool
by thermal shock;
• Do not operate the main relief valve and overload
relief valve abruptly without a proper time interval. Let
the hydraulic oil circulate in each actuator to warm up
all the parts uniformly.
• Fine or complex operations which may cause local
overheating at the orifices of each part should not be
done abruptly at low temperature.
Main Control Valve
SP001029
Page 47