{TAIL ~ A nonmetallic resilient sleeve} surrounds the bolt between the flanges and a nonmetallic cover overlies {HEAD ~ at least the outer surface} of the outer flange 
{ TAIL ~ A nonmetallic resilient sleeve } surrounds the bolt between the flanges and a nonmetallic cover overlies { HEAD ~ at least the outer surface } of the outer flange
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH