Large-diameter one-time-formed 180-degree elbow and machining process thereof

Abstract

The invention relates to the technical field of elbows, in particular to a large-diameter one-time-formed 180-degree elbow, which comprises an elbow body provided with a longitudinal welding seam in the extending direction of the elbow body. A machining process of the large-diameter one-time-formed 180-degree elbow comprises the following steps that step 1, a rectangular steel plate is selected and used, the rectangular steel plate is rolled into a cylinder shape, and a cylinder is manufactured; step 2, the butt joint faces of the cylinders in the first step are welded, and a base metal pipe fitting is obtained; and step 3, a hot-bending pipe bending machine is adopted for carrying out hot forming on the base material pipe fitting in the second step, the base material pipe fitting is machined to have the needed bending degree, no cross-shaped welding seam is contained, only longitudinal welding seams are contained, one-time forming is achieved, and the pressure bearing capacity is improved.

Description

technical field [0001] The invention relates to the technical field of elbows, in particular to a 180-degree elbow with a large diameter formed at one time and a processing technology thereof. Background technique [0002] As we all know, large-diameter 180-degree elbows are commonly used in pressure piping installations. Most of the existing large-diameter seamed 180-degree elbows are welded by two 90-degree elbows and a girth weld. , because of the large caliber, the 90-degree elbow is generally provided with two longitudinal welds, which are respectively located on the outer arc and inner arc of the elbow, and the position of the welds cannot be adjusted to other positions. The girth weld and the longitudinal weld intersect, thereby inevitably forming two "ten" welds. The "ten" weld is explicitly prohibited in the pressure vessel standard, but for large-diameter elbows, there is no large-diameter pipe Due to the limited technology, the current large-diameter elbow still ...

AI Technical Summary

Problems solved by technology

[0002] As we all know, large-diameter 180-degree elbows are commonly used in pressure piping installations. Most of the existing large-diameter seamed 180-degree elbows are welded by two 90-degree elbows and a girth weld. , because of the large caliber, the 90-degree elbow is generally provided with two longitudinal welds, which are respectively located on the outer arc and inner arc of the elbow, and the position of the welds cannot be adjusted to other positions. The girth weld and the longitudinal weld intersect, thereby inevitably forming two "ten" welds. The "ten" weld is explicitly prohibited in the pressure vessel standard, but for large-diameter elbows, there is no large-diameter pipe Due to the limitation of the process, the current large-diameter elbow still has a "ten" weld

Images