Abstract: In the proposed method, a protective sleeve is plastically deformed to dimensions enabling the shape of the sleeve to correspond to the shape of the interior surface of the pipes to be joined in the joint region. The deformed sleeve is installed inside the pipes to be joined such that an annular cavity is formed between the sleeve and the region of the welded joint together with the adjacent portions of the pipes protected by a coating. The ends of the pipes are joined by welding and the annular cavity is hermetically sealed at the ends of the sleeve. Once sealed, the cavity is evacuated and, via working apertures in one or both of the pipes to be joined, the annular cavity is filled with a liquid sealing material, which is then polymerized.