METHOD FOR REPAIRING INNER TUBE SURFACE AND FOR PRODUCING BAND FOR INNER TUBE SURFACE REPAIRING Russian patent published in 2004 - IPC

FIELD: tube repairing works, particularly for performing well and pipeline repairing works.

SUBSTANCE: method of well repairing includes delivering preliminary deformed bandage to tube damaged area; fixing band by heating thereof, which results in initial band shape reconstruction. Heating is carried out in several steps with initial heating areas located proximate to longitudinal band axis. Band has cylindrical shape and is formed of sheet blank made of shape-memory alloy, which obtains initial cylindrical shape. Band is preliminary deformed under isothermal conditions in martensitic phase symmetrically to longitudinal band axis to obtain smoothly corrugated band surface. Ratio of specified initial band diameter to diameter of deformed band is not less than 0.8 - 0.85. Ratio of band corrugation diameter to double thickness of sheet band blank is more or equal to 5. Band is made of one or several blanks with ends connected by wedge-dovetail connection. Wedge-like blank end has bead extending along wedge-like end tip. Dovetail-like end has groove extending along dovetail valley and mating to bead of wedge-like end. Dovetail connection is reinforced additionally by welding. Cross-section of sheet blank has smooth inclination directed from ends to center thereof in area between wedge-like and dovetail areas.

EFFECT: simplified band production and installation, reduced time of repairing works performing, minimized change of initial tube cross-section, increased reliability, extended service life of well or tube.

6 cl, 8 dwg, 1 tbl