A gas fired tube and shell heat exchanger directs a flame directly into an inlet end of the tube bundle and {HEAD ~ the flame} and exhaust are drawn through {TAIL ~ the tube bundle} by an induced draft blower located in the exhaust stream outside of the shell 
are drawn through
A gas fired tube and shell heat exchanger directs a flame directly into an inlet end of the tube bundle and { HEAD ~ the flame } and exhaust are drawn through { TAIL ~ the tube bundle } by an induced draft blower located in the exhaust stream outside of the shell
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH