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