The chamber is sealed and {HEAD ~ a heater} causes the liquid within {TAIL ~ the chamber} to vaporize 
The chamber is sealed and { HEAD ~ a heater } causes the liquid within { TAIL ~ the chamber } to vaporize
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH