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