A valve box 6 constitutes means for connecting the pump chamber 5 to {HEAD ~ a suction pipe} via at least one check valve that allows fluid to pass in {TAIL ~ direction} A 
A valve box 6 constitutes means for connecting the pump chamber 5 to { HEAD ~ a suction pipe } via at least one check valve that allows fluid to pass in { TAIL ~ direction } A
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH