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