Bi-metal pipeline and pipe fitting beveling method and bi-metal pipeline and pipe fitting assembly

Abstract

A bi-metal pipeline and pipe fitting beveling method is used for a bi-metal pipeline and a bi-metal pipe fitting. The bi-metal pipeline and the bi-metal pipe fitting each comprise a base layer and a composite layer. Each base layer is made of one of carbon steel, alloy steel and stainless steel. Each composite layer is made of nickel-based alloy or stainless steel. The beveling method comprises the first step that primary beveling is conducted on the base layer and the composite layer of the end face of the bi-metal pipeline or the bi-metal pipe fitting, and the end face is called a beveled end face after primary beveling. The problem of circular seam leakage caused by misalignment can be solved, and the circular seam installation quality is guaranteed.

Description

technical field [0001] The invention relates to the field of pipelines, in particular to a bimetallic pipeline and pipe fittings. Background technique [0002] In recent years, with the rapid development of petroleum, natural gas, chemical industry, and ship development, the corrosion environment of pipelines has put forward higher and more stringent corrosion resistance requirements for pipelines. At present, most of them are bimetallic pipelines, which are resistant to corrosion and wear. Especially strong, suitable for marine, petroleum, chemical, pharmaceutical, electric power, natural gas transmission, aerospace industry, shipbuilding, etc., but the bimetallic pipeline is divided into two parts: the base layer and the layered layer. When the diameter difference of the pipe fittings is within the standard range And when the misalignment of the welding joints of the pair reaches 0-4mm, the thickness of the cladding layer is only 2-4mm. There are 0-2mm, and sometimes due ...

AI Technical Summary

Problems solved by technology

[0002] In recent years, with the rapid development of petroleum, natural gas, chemical industry, and ship development, the corrosion environment of pipelines has put forward higher and more stringent corrosion resistance requirements for pipelines. At present, most of them are bimetallic pipelines, which are resistant to corrosion and wear. Especially strong, suitable for marine, petroleum, chemical, pharmaceutical, electric power, natural gas transmission, aerospace industry, shipbuilding, etc., but the bimetallic pipeline is divided into two parts: the base layer and the layered layer. When the diameter difference of the pipe fittings is within the standard range And when the misalignment of the welding joints of the pair reaches 0-4mm, the thickness of the cladding layer is only 2-4mm. There are 0-2mm, and sometimes due to the influence of positive and negative values, the misalignment is serious, and the effective thickness of the cladding layer is 0, which causes the welding of the cladding layer and the base layer, causing the leakage of the girth weld of the pipeline to be very serious after operation, and resulting in weld seams The material changes, and the corrosion resistance of the weld is also greatly reduced

For example, in the standard, when the nominal diameter of the pipe fitting is 650-750, the inner diameter of the end is ±2.0. Within the standard range, there are exactly 4 values ​​between +2 and -2, and the cladding thickness is only 2-4mm. It is easy to cause wrong edge phenomenon

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