The cap includes {TAIL ~ a transverse top wall} which is spaced from the top edge of the inner wall to provide an overflow path for surges of liquid and {HEAD ~ gas} 
The cap includes { TAIL ~ a transverse top wall } which is spaced from the top edge of the inner wall to provide an overflow path for surges of liquid and { HEAD ~ gas }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD