A fluid flow controlling device having {HEAD ~ a working member} capable of reciprocating in {TAIL ~ a tubular case} 
capable of reciprocating in
A fluid flow controlling device having { HEAD ~ a working member } capable of reciprocating in { TAIL ~ a tubular case }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL