Hole repairing construction machine for polyethylene anti corrosive coating of metallic tube and construction method thereof

Abstract

The invention provides a hole repairing construction machine for a polyethylene anti corrosive coating of a metallic tube and a construction method thereof. A main body of the hole repairing construction machine consists of a tubular pressurizing sleeve and a tubular rubber air bag adhered to the inner wall of the main body; and the pressurizing sleeve and the rubber air bag are kept coaxial with the tube by four support arms arranged on each of the two sides of the pressurizing sleeve along the axial direction of the tube and rubber rolling wheels arranged at the tail ends of the pressurizing sleeve, and a polyethylene hole repairing band is artificially inserted in the pressurizing sleeve from the side of longer support arms and closely attached to the inner wall of the rubber air bag by the recurrent force of the polyethylene hole repairing band. The polyethylene hole repairing band may be of an electric heating fusion shrinking type or external heating shrinking type, the rubber air bag is pressurized by air compression equipment and a thermal conduction oil pump, and after the polyethylene hole repairing band is electrified for heating fusion or fused by the heat transfer of the thermal conduction oil, the rubber air bag is gradually pressurized to 0.01 to 1MPa until the adhesion is completed. In the hole repairing process of the invention, main operational steps are automatically completed by the equipment, and the construction quality is good; and the polyethylene hole repairing band withstands a huge pressure in a softening process, so that the bonding strength is greatly improved, and the cost is also low.

Description

technical field [0001] The invention relates to the technical field of anticorrosion of metal pipelines, in particular to an on-site repairing construction tool and construction method for polyethylene anticorrosion layers of steel pipelines with a two-layer or three-layer structure. Background technique [0002] At present, two-layer extruded polyethylene anti-corrosion coating (2LPE) and three-layer extruded polyethylene anti-corrosion coating (3LPE) are the most widely used and effective external anti-corrosion technologies for buried steel pipelines. The 3LPE anti-corrosion layer consists of epoxy powder coating, polyethylene adhesive and high-density polyethylene for pipeline anti-corrosion in sequence from the inside to the outside, while the 2LPE anti-corrosion layer has one layer of epoxy powder coating less than the former. 3LPE and 2LPE anti-corrosion technology can only be applied to straight pipes. The length of the straight pipe is limited, and the pipes need t...

AI Technical Summary

Problems solved by technology

3LPE and 2LPE anti-corrosion technology can only be applied to straight pipes

Radiation cross-linked polyethylene shrinkage tape (sleeve) has many disadvantages. First of all, the jointing process is manual operation, steel pipe preheating and heat shrinkable tape (sleeve) baking are generally heated by flames, and the temperature accuracy and uniformity are difficult to be accurate. control, which greatly affects the quality of the joint, and even burnt damage in severe cases

Secondly, when the cross-linked polyethylene substrate is heated, the elastic shrinkage force is not large, the pressure exerted on the hot melt adhesive is limited, and the bonding strength is much lower than that of the 3LPE or 2LPE anti-corrosion layer, which often becomes the weak link of the entire pipeline anti-corrosion

Finally, the heat-shrinkable tape (sleeve) of radiation cross-linked polyethylene must be produced through multiple processes such as extrusion molding, radiation cross-linking, diameter expansion, cooling, and glue coating. cause some damage

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