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