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