A water flow sensing unit is secured between {TAIL ~ the inlet port} and {HEAD ~ the flow discharge port} 
A water flow sensing unit is secured between { TAIL ~ the inlet port } and { HEAD ~ the flow discharge port }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD