Komatsu PC500LC-10R Shop Manual page 282

COMPONENT PARTS OF HYDRAULIC SYSTEM
FUNCTION OF MAIN RELIEF VALVE OF CONTROL VALVE
• The set pressure is changed to 2 stages.
• When power is required, high pressure is set by receiving pilot pressure (P) from the 2-stage relief solenoid
valve.
• The set pressure of the relief valve depends on the load at installed height of the spring (1). (The first level)
• When the 1st stage is set again, as for the 2nd stage as well, the set pressure of the same amount as in-
crease and decrease of the 1st stage changes.
OPERATION OF MAIN RELIEF VALVE OF CONTROL VALVE
When pilot pressure (P) is cut off (low pressure setting)
The set pressure is determined by the installed load of spring (1).
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10 STRUCTURE AND FUNCTION
PC500LC-10R