CONNECTION OF PIPES WITH INTERNAL COATING AND METHOD OF ITS IMPLEMENTATION Russian patent published in 2016 - IPC F16L13/02 

FIELD: production of fittings.

SUBSTANCE: invention relates to pipeline valves and can be used in construction of pipelines for transportation of liquid aggressive media, particularly for oil pumping, gas-condensate mixture, etc. Welded joint of pipes with internal heat-sensitive coating includes two pipes, connecting enameled bushing, wherein ring branch pipes corresponding to brand chemical composition and dimensional values of connected pipes are welded between connected pipes ends and connecting bushing to pipes ends. Branch pipes inner surface in bushing length section (3.1-3.5) has high temperature silicate enamel coating of bushing enamel composition. On side of non-enamelled section branch pipes are welded to pipes ends using circular seam, “branch pipe-pipe-branch pipe” weld joint is subjected to inner surface mechanical cleaning and subsequent application of heat-sensitive coating onto this surface with partial overlapping of branches enamelled section. Connection of pipes into string is performed by means of connection enameled bushing welding with annular branch pipes without fusion of inner heat-sensitive layer.

EFFECT: connection of pipes with internal heat-sensitive coating and method of its implementation provides simple and reliable welded joint and joint inner surface anticorrosion protection against effects of pumped aggressive fluids.

2 cl, 1 dwg, 1 tbl