The steam boiler operates at {HEAD ~ a pressure} above that needed for consumption in the process chamber and uses {TAIL ~ highly purified water} 
The steam boiler operates at { HEAD ~ a pressure } above that needed for consumption in the process chamber and uses { TAIL ~ highly purified water }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL