Thus, when the valve is closed, {HEAD ~ current} flows from electrode 140 to {TAIL ~ electrode} 142 through strip 145 
Thus , when the valve is closed , { HEAD ~ current } flows from electrode 140 to { TAIL ~ electrode } 142 through strip 145
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH