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