The excavator pilot pump pushes the main control valve block stem (distribution valve) through the pilot ppc valve (handle, foot valve), and sends the high-pressure oil output from the main pump to the designated working device, such as the boom, forearm, shovel Bucket, swing motor, walking motor.
https://www.dtsanyparts.com/slewing-device/cab/pilot-control-foot-valve-for-sy215c.html