As the housing is heated, {TAIL ~ the different coefficents} of thermal expansion of components of the housing cause the joint between {HEAD ~ the workpiece} and housing sections to be sealed 
As the housing is heated , { TAIL ~ the different coefficents } of thermal expansion of components of the housing cause the joint between { HEAD ~ the workpiece } and housing sections to be sealed
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH