The valve member, which may be formed from {HEAD ~ a single piece}, may define {TAIL ~ an enlarged portion} retaining the seal and a stem retaining the bias means 
The valve member , which may be formed from { HEAD ~ a single piece } , may define { TAIL ~ an enlarged portion } retaining the seal and a stem retaining the bias means
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH