PIPELINE RESTORATION METHOD Russian patent published in 2001 - IPC

FIELD: repairing gas conduits, oil condensate conduits and other cylindrical metallic constructions such as vessels, reservoirs and so on. SUBSTANCE: method comprises steps of repairing pipeline with use of coupling mounted onto repaired portion of pipeline in order to apply controllable load reducing said coupling due to use elastic chamber filled with pressurized liquid or gas; preliminarily measuring residual pressure in pipeline and remained thickness of repaired portion; determining value of reducing pressure in elastic chamber according to relation , where Pop - operational pressure in pipeline, MPa; Pres - residual pressure in repaired pipeline, MPa; t₁ -equivalent remained thickness of repaired pipeline, mm; t₂ - coupling thickness, mm; Rout - outer radius of pipeline, mm; Rin - inner radius of pipeline, mm; E - elasticity modulus of pipeline material, MPa; L' - distribution length of zone of "eddy effect", mm; a -length of portion for applying reducing load to coupling along axis of pipeline, mm; f -friction factor at sliding of coupling along pipeline; ε_r.d.- mean relative deformation values of pipeline caused by thermal shrinkage of welded seam of coupling; σ_result -resulting annular stresses of pipeline wall after mounting coupling, MPa. EFFECT: enhanced strength and stability of repaired portion. 4 dwg