A seal is installed in the groove on {TAIL ~ the open end} of the cup to seal to the primary face of a tubesheet around {HEAD ~ the tested rib plug} 
A seal is installed in the groove on { TAIL ~ the open end } of the cup to seal to the primary face of a tubesheet around { HEAD ~ the tested rib plug }
OTH OTH 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 OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD