FIELD: repair and restoration of functions of apparatus attacked by internal corrosion during operation at high and medium pressure. SUBSTANCE: method includes the following operations: (1) cleaning corroded area; (2) forming bearing or holding surfaces on cleaned area for placing new metallic lining; (3) making new anticorrosion hermetic lining from flat members and metal plates of respective form; abutting these plates on inner surface of apparatus and welding them together in such way that intermediate cavities under lining are connected with at least one seepage hole made in housing of apparatus. All repair jobs are performed through hatch of apparatus. As a result, functions of apparatus are restored for period of time close to specified service life of new apparatus. Shaped members of new envelope are tightly connected with housing and are welded together in such way that weld has at least one section of incomplete penetration which is covered by metal cover plate welded to new lining. Apparatus may be made in form of section of high and medium pressure or in form of reactor. EFFECT: enhanced efficiency. 17 cl, 6 dwg
