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