Heating coils 63 surround tube 37 to heat {HEAD ~ tube} 37 to {TAIL ~ a desired temperature} 
to
Heating coils 63 surround tube 37 to heat { HEAD ~ tube } 37 to { TAIL ~ a desired temperature }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL