The formed welded unit may then be placed in a mold that consists of two halves to facilitate formation of {HEAD ~ an internal flexible membrane} that defines {TAIL ~ part} of the valve 
The formed welded unit may then be placed in a mold that consists of two halves to facilitate formation of { HEAD ~ an internal flexible membrane } that defines { TAIL ~ part } of the valve
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH