C) sealing {HEAD ~ the hole} by connecting one end of a tube of a predetermined length to the outside of the burr, compressing {TAIL ~ the protruding end} of the tube, and then welding the compressed part of the tube 
C ) sealing { HEAD ~ the hole } by connecting one end of a tube of a predetermined length to the outside of the burr , compressing { TAIL ~ the protruding end } of the tube , and then welding the compressed part of the tube
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH