Abstract: In a method of repairing a scroll compressor, the casing 100 of the compressor is cut open by making two transverse cuts through the casing to give access to the internal components of the compressor. The casing 100 is then resealed, using two annular reinforcing structures 300, one at each cut, to conserve the dimensions of the casing 100. This allows a scroll compressor to be repaired and re-assembled without losing the fine positioning of internal components which are held in place by the casing 100. Each annular reinforcing structure 300 comprises a ring 310 with an outwardly directed flange 305. The flange 305 has a thickness chosen to conserve the dimensions of the re-assembled casing while allowing single-pass welding and the ring 310 has a length which is chosen to provide at least location of the cut surfaces of the casing 100 during re-assembly and, optionally, shielding to prevent weld pool, slag or splatter entering the canister 100.