1) First fit up three cylindrical shell segments, ensure that the long-arm submerged arc welder can reach the welding location.
2) Fix the shell segments together with spot welding from the outside.
3) Weld the joints from the insdie of the shell with submerged arc welding, and clean the joints from the outside with carbon arc air gouging and polish with a grinding wheel, then weld with submerged arc welding.
4) After welding, 3 to 4 circular welding support brackets can be removed, but the two at both ends must be retained.
5) Subsequently, add one or two cylindrical shell segments at one time for welding, provided that the long arm submerged arc welder can reach the welding locations.
6) By analogy, circumferencial welding support brackets shall be scattered evenly inside the cylindrical shell.
7) For surface repair and grinding of all welds, 20% radiographic test by grade III shall be performed.
8) After the flaw detection, fit up the stiffening rings, fix the rings with the mixed gas protection spot welding first, then intermittent welding of 80%.
9) Mark out and then cut out the openings of nozzles. The opening positions shall be no less than 100mm away from any welds. The groove of the openings shall be polished with grinding wheel and grinding head. Fit up the nozzles for explosion-proof devices and perlite powder filling, spot weld manually first then full weld manually, with welding wire H10Mn2. Upon completion, run 100% dye penetration test.
10) After degreasing the surface of the inner , the transition pipe shall be sealed from the outside with self-adhesive tape, and the ends of the cylinder shall be sealed with plastic sheets.
