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