STRUCTURE, FUNCTION, & MAINTENANCE STANDARD SELF PRESSURE REDUCING VALVE SELF PRESSURE REDUCING VALVE FUNCTION This value reduces the discharge pressure of the main pump and supplies it as control pressure for the solenoid valves, PPC valves, etc.. OPERATION 1. When engine is stopped Puppet (11) is pressed by spring (12) against the seat and port PR is not connected to TS. Valve (14) is pressed by spring (13) against the left side and port P2 is connected to PR. Valve (7) is pressed by spring (8) against the left side and port P2 is not connected to A2. (See Fig. 1.) PC210/240-7K 10-83