Manufacturing method of steel rotational moulding pipeline with polyolefin lining layer

Abstract

The invention relates to a manufacturing method of a steel rotational moulding pipeline with a polyolefin lining layer, comprising the following steps: welding, sandblasting, heating and preserving the temperature, rotationally moulding, lowering the temperature, carrying out a pressure test under negative pressure, carrying out a pressure test under a positive pressure, detecting the lining and the like. The pipeline obtained by utilizing the method in the invention not only has the strength of steel, but also has corrosion resistance property of plastics, and is resistant to acid, alkali and salt of various concentrations and some organic solutions in the range from minus 60 DEG C to 100 DEG C. The pipeline in the invention is an ideal material to substitute rubber, fibre reinforced plastic, stainless steel, titanium timber and brick lining, is stable for long-term use in strong corrosive mediums such as various organic acid, inorganic acid, alkali salt and the like, and is characterized by acid-base mixing, shock cooling or heating or alternation of cold and hot.

Description

technical field [0001] The invention relates to the technical field of pipe manufacture, in particular to a method for manufacturing a steel rotationally molded pipe with a polyolefin inner liner. Background technique [0002] For a long time, pipeline corrosion has been one of the most troublesome hazards in the chemical industry. A little carelessness can damage equipment, cause accidents or even disasters. From the perspective of the type of corrosion, in the piping of various devices, the general corrosion is the most; followed by local corrosion and special corrosion. [0003] Corrosion of piping generally occurs in the following places: [0004] 1. The bending part of the piping, the turning part, and the part of the streamlined pipe section where liquid flows in and the flow direction changes are prone to corrosion; [0005] 2. When gasification occurs, the parts in contact with liquid are more likely to be corroded than the parts in contact with steam; [0006] 3....

AI Technical Summary

Problems solved by technology

[0004] 1. The bending part of the piping, the turning part, and the part of the streamlined pipe section where liquid flows in and the flow direction changes are prone to corrosion;

[0005] 2. When gasification occurs, the parts in contact with liquid are more likely to be corroded than the parts in contact with steam;

[0006] 3. In the discharge pipe, there is often localized corrosion in the pipe section where there is often no liquid flow;

[0007] 4. Liquid or steam piping used in a state of temperature difference often suffers from severe local corrosion;

[0008] 5. The outer lower surface of the buried pipeline is most prone to rapid corrosion

[0009] The existing steel-lined plastic pipes are almost all loose-lined, not only the flanging is uneven, but also not resistant to negative pressure