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