METHOD OF TRENCHLESS SANITIZATION OF WORN-OUT PIPELINES Russian patent published in 2020 - IPC F16L55/165 F16L1/32 

FIELD: pipelines.

SUBSTANCE: method involves preliminary cleaning of pipeline equipped with flanges of sanitized section with further broaching of non-metallic liner. Length of the liner, after drawing through the sanitized section of the pipeline, is made larger than the length of the named section by value l_k, determined by the proposed mathematical expression. Stretching is performed so that from each end of section of sanitized pipeline the liner projects outwards by value 0.5 l_k adjacent to both end steel flanges of the sanitized section of the pipeline. Metal yokes securing the liner section located inside the sanitized pipeline are installed on the sections of the liner projecting outside the flanges. Polyethylene bushings are welded to the ends of the liner protruding sections, after which the yokes are removed. Then liner bush, which has reducing properties under any climatic conditions of operations, expanding in diameter and reducing length under action of temperature deformation, tightly adjacent to surface of steel flanges of pipeline. Steel flanges of the sanitized sections of the pipeline are connected, for example, with a bolt joint, thus ensuring tightness of joints. Reclamation of pipeline sections up to 1000 m long is possible. Along the length of the liner, longitudinal furrows are made having depth that does not affect its strength. Liner can be a polyethylene liner with specified properties.

EFFECT: invention relates to repair and reconditioning of worn-out pipelines by trenchless method, as well as protection of new pipelines against corrosion and rivulets wear at performance of works in conditions of cold climate of Siberia.

5 cl, 4 dwg