{HEAD ~ a nonmetallic cover} overlying {TAIL ~ at least the outer surface} of the outer flange; and 
overlying
{ HEAD ~ a nonmetallic cover } overlying { TAIL ~ at least the outer surface } of the outer flange ; and
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH