The unidirectional pressure sensitive valve 2, in which {TAIL ~ said device} is {HEAD ~ a pump} 
The unidirectional pressure sensitive valve 2 , in which { TAIL ~ said device } is { HEAD ~ a pump }
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD