METHOD OF COMPLEX CORROSION PROTECTION OF EXTENDED STEEL PIPE LINES (VERSIONS) Russian patent published in 2007 - IPC C23F17/00 

FIELD: corrosion protection of metals; protection of steel gas and oil pipe lines against corrosion.

SUBSTANCE: proposed method includes preparation of pipe edges, drying, cleaning, machining of internal surfaces of pipes, finish cleaning, application of main metallic coat near edge of pipe followed by application of additional coat overlapping the first one, heating the pipe to melting point of insulating plastic coat and applying one layer of insulating plastic coat on inner surface of pipe partially overlapping the main metallic coat; machining of outer surface of pipe, cleaning and applying layer of insulating plastic coat and erecting the pipe line; then, pipe edges are heated and aligned, after which they are welded and root runs of the weld seams are machined; welded joint is heated and filling and facing layers of weld seam are welded; then, they are cooled and non-insulated outer surface of pipe is protected by plastic insulating coats. According to another version, melt of polymer composition is applied on heated surface of pipe, after which plastic bearing and centering rings are wound on pipe and are rolled to it. Ratio of height, width of top and base of bearing ring to pipe outer diameter is equal to 1: (0.01-1.35); 1: (0.07-1.6) : (0.1-2.0), respectively; ratio of width of top and base of bearing ring is equal to 1 : (1-2.0); after erecting of pipe line, protection of its inner surface is effected by pumping an inert medium through it.

EFFECT: low labor input; improved quality of corrosion protection; enhanced reliability of pipe lines.

14 cl, 4 dwg, 4 tbl