Komatsu PC500LC-10R Shop Manual page 304

COMPONENT PARTS OF WORK EQUIPMENT SYSTEM
1: Spool
2: Piston
3: Lever
4: Plate
OPERATION OF 1ST-LINE ATTACHMENT PPC VALVE (WITH EPC VALVE)
REMARK
For explanation of operation of PPC valve, see "Operation of work equipment and swing PPC valve".
EPC VALVE OF 1ST-LINE ATTACHMENT PPC VALVE
PPC
Abbreviation for Proportional Pressure Control
EPC
Abbreviation for Electromagnetic Proportional Control
STRUCTURE OF EPC VALVE OF 1ST-LINE ATTACHMENT PPC VALVE
(Machines ready for installation of attachment)
10-210
10 STRUCTURE AND FUNCTION
5: Retainer
6: Body
7: EPC valve
PC500LC-10R