by pressing the pusher by the operating portion to cause the spool to slide, {HEAD ~ liquid pressure} from the pump port is supplied to {TAIL ~ the output port} 
by pressing the pusher by the operating portion to cause the spool to slide , { HEAD ~ liquid pressure } from the pump port is supplied to { TAIL ~ the output port }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL