PROCEDURE FOR ANTI-CORROSION INSULATION OF WELDING JOINT OF PIPELINE AND FACILITY FOR ITS IMPLEMENTATION Russian patent published in 2010 - IPC F16L58/02 

FIELD: machine building.

SUBSTANCE: first, before welding end of pipeline, heat-shrinkage clutch-bushing is positioned on pipeline close to joint. Upon joint welding, insulated surface is cleaned with metal brushes and dried from moisture. Prime coating - "liquid" primer and mastic band corresponding to coating with 80…90 degrees C temperature of mastic material softening are applied on this surface. Further, the heat-shrinkage clutch-bushing is pushed to a zone of a welded joint symmetrically to it and is heated to temperature 110…120 degrees C. Simultaneously, layers of the mastic band are heated and melted through the heat-shrinkage clutch-bushing ensuring pressure onto melted mastic of the mastic band and filling interstices with it in a zone of welding joint strengthening (hemi-spherical zones) and places of transition to base coating and overlapped layers of the mastic band. Insulating coating of the welded joint of the pipeline contains prime coating- "liquid" primer, the mastic band made either in from of a polymer-bitumen with base out of polyvinylchloride with mastic of 80…90 degr. C of softening, or in form of a base-less material consisting of polymer-bitumen mastic with softening temperature 80-90 degrees C and glass mesh. Also insulating coating consists of the heat-shrinkage clutch enveloping the pipeline and made in form of a solid bushing out of a sheet of light- and heat stabilised one-layer polyethylene modified by radiation-chemical method. The clutch is installed on the pipeline before pipeline joint welding and can travel along axis of the pipeline.

EFFECT: raised efficiency of anti-corrosion protection due to increased resistance of insulation coating.

2 cl, 2 dwg