When the valve is closed, {HEAD ~ current} flows from electrode 340 to {TAIL ~ electrode} 342 through conducting ball 345 
flows to
When the valve is closed , { HEAD ~ current } flows from electrode 340 to { TAIL ~ electrode } 342 through conducting ball 345
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 OTH