A trough 28 has a pair of rectangular holes 29 formed through opposed sides thereof, for captively receiving flanges 27 therethrough, preventing rotation of {HEAD ~ cylindrical valve member 24b} with respect to {TAIL ~ trough} 28 
A trough 28 has a pair of rectangular holes 29 formed through opposed sides thereof , for captively receiving flanges 27 therethrough , preventing rotation of { HEAD ~ cylindrical valve member 24b } with respect to { TAIL ~ trough } 28
OTH OTH OTH OTH OTH OTH 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 OTH OTH TAIL TAIL TAIL TAIL TAIL OTH