METHOD FOR REPAIRING HEAT RECOVERY STEAM GENERATOR TUBE-TO-HEADER DAMAGE

摘要

A method for repairing a heat recovery steam generator (HSRG) header to tube attachment damage, includes providing an access window (31) in the header (11) opposite the damaged header to tube attachment location; removing the header to tube attachment damage; inserting a tapered stub tube (40) into a header penetration centered axially immediately over the tube; effecting a profile weld between the header and the tapered stub tube at the header penetration from the inside surface of the header; welding the tapered stub tube to the existing tube (12) through the header inside diameter; welding shut the access window; and completing a post weld heat treatment of all the welds.