In {HEAD ~ the absence} of pressurized water flow, the bar magnet drops into magnetic field coupling {TAIL ~ proximity} with the reversing reed switch SW2 
In { HEAD ~ the absence } of pressurized water flow , the bar magnet drops into magnetic field coupling { TAIL ~ proximity } with the reversing reed switch SW2
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH