In one aspect, {HEAD ~ the invention} is {TAIL ~ a device} for controlling a flow of a fluid moving through a pipe 
is
In one aspect , { HEAD ~ the invention } is { TAIL ~ a device } for controlling a flow of a fluid moving through a pipe
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH