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