When {TAIL ~ a filling level} of fuel reaches {HEAD ~ the closing part} 16, the latter is pressed against the valve seat 15 and closes the valve 11 
When { TAIL ~ a filling level } of fuel reaches { HEAD ~ the closing part } 16 , the latter is pressed against the valve seat 15 and closes the valve 11
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH