When the parameter to be sensed reaches a predetermined value or {HEAD ~ configuration}, the switching apparatus may, by means of {TAIL ~ electronic signals}, cause the first valve apparatus to close 
When the parameter to be sensed reaches a predetermined value or { HEAD ~ configuration } , the switching apparatus may , by means of { TAIL ~ electronic signals } , cause the first valve apparatus to close
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH