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