During the mechanical cycles, the packing temperature was subjected to {TAIL ~ varying thermal cycles} repetitively between the ambient temperature and {HEAD ~ 450° F.}  
During the mechanical cycles , the packing temperature was subjected to { TAIL ~ varying thermal cycles } repetitively between the ambient temperature and { HEAD ~ 450 ° F. }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH