The middle nozzle provides water, air or {HEAD ~ other chemicals} as coolant to insulate {TAIL ~ the inner nozzle} 
to insulate
The middle nozzle provides water , air or { HEAD ~ other chemicals } as coolant to insulate { TAIL ~ the inner nozzle }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL