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