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