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