A Welding Process of Large-diameter Thin-walled Double Tube Sheet and Cylinder Circumferential Seam

Abstract

The invention discloses a large-diameter thin-wall double-tube sheet and cylinder body circular seam welding process. The large-diameter thin-wall double-tube sheet and cylinder body circular seam welding process comprises following steps of firstly, assembling, wherein two sets of pie plates and cylinder joints are assembled in place, grooves of the pipe plates and the cylinder joints are same, and the pipe plates in the same group and the cylinder joints are subjected to spot welding fixing through multiple tie bar plates; secondly, connection, wherein the front faces of two pipe plates cling together, multiple pull rods are adopted to penetrate through pipe holes of two pipe plates, two ends of the pull rods are fastened through nuts, and relative positions of the two pipe plates are fixed; thirdly, welding, wherein annular seam welding of more than two times are carried out in the grooves of each set of pipe plates and the cylinder joints, and annular seam welding of the two sets of pipe plates and the cylinder joints is alternatively carried out; fourthly, heat treatment, wherein annular seams of the two sets of pipe plates and the cylinder joints are subjected to heat treatment; and fifthly pull rod and tie bar plate dismounting and mounting. Deforming of the pipe plates can be greatly reduced, the hole position matching degree of the two pipe plates and the subsequent pipe penetrating smooth operation can be ensured, construction is easy and convenient, work efficiency is high, and manufacturing cost is greatly reduced.

Description

technical field [0001] The invention relates to a circular seam welding process between a double-tube sheet and a cylinder body, in particular to a circular seam welding process for a super-large-diameter thin-walled double-tube sheet and a cylinder body. Background technique [0002] In many large-scale chemical equipment, there are more and more ultra-large thin-walled double-tubesheet projects. Thin-walled double tube sheet equipment has large volume, large diameter and heavy equipment. The diameter of the tube sheet is very large, but the thickness of the tube sheet is very thin, and the diameter-thickness ratio of the tube sheet is very large, and some of the diameter-thickness ratios have reached 25-30. ) In contrast, the rigidity of the tube sheet of this type of large-diameter thin-walled double-tube sheet equipment is very poor. This type of tube sheet has large openings and a large number of holes, and the welding of the tube sheet and the shell-side tubular join...

AI Technical Summary

Problems solved by technology

The traditional process is: adopt the tie rod fixing method, that is, weld the fixed plate inside the cylinder, put the tube plate and the fixed plate close together, several pull rods pass through the tube plate and the fixed plate and lock them with nuts, and carry out the circular seam between the cylinder body and the tube plate Welding; but when removing the fixing plate, because the fixing plate is firmly welded, the workload of removal, grinding and repairing is very large, and the material and thickness of the equipment shell need to be preheated before welding before repairing. It is more difficult to repair the equipment that requires heat treatment before the body ring seam

For double tube sheets, the matching degree of the holes of the two tube sheets is very important and needs to be guaranteed; The rigidity behind the hole is too poor, the diameter-thickness ratio of the tube sheet is too large, and the welding of the girth seam will cause the deformation of the tube sheet. The most serious deformation of the tube sheet is even greater than 20 mm. position, causing the equipment to fail to pass through the pipe smoothly

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