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