{HEAD ~ Further release} of {TAIL ~ gas} and stratification of the oil and water occurs within the post heating zone 32 
{ HEAD ~ Further release } of { TAIL ~ gas } and stratification of the oil and water occurs within the post heating zone 32
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH