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