SU770623A1 - Method of producing super out-sized multilayer high pressure vessel housing and tubes - Google Patents

Description

(54) METHOD OF MANUFACTURING OVERALL-SIZE MULTILAYERED CASES OF HIGH-PRESSURE VESSELS AND PIPES The invention relates to the production of multi-layer vessels and pipes and can be applied in the energy-chemical and petrochemical industries. There is a known method of manufacturing multi ply vessels, in which a cold shell of an open, closed shell or two half-cylinders with a sheet thickness up to 6 mm is put on the base pipe and tightened with braided lines and brewed with longitudinal shyami. On the cell is repeated successively until the total thickness of the structure reaches the required calculated one. The disadvantage of the known method is the need to manufacture a rigid base pipe, the need to manufacture a large number of items and sizes of parts constituting the body, the need to use special tightening devices, the difficulty of monitoring and repairing internal seams during operation, etc. pressures from multi-layered flanks, on the welded ends of which ledges 2 are made. In this method, the grooves and protrusions on the end surfaces are formed by mechanical processing of cylindrical multilayer pipes. The disadvantages of this. The method consists in requiring increased accuracy of the mechanical equipment to form a complex profile on the end surfaces; the utilization rate of the base metal is reduced by removing its part when preparing the edges for welding; the application of the method is limited due to the insufficient strength of the welded joint (incomplete shear) under triaxial loading. The closest solution to the proposed method is to manufacture with: high-capacity multi-layer high-pressure vessels, in which multi-layer sections are assembled from individual sheets, bent along the curvature radius of the vessel, and then welded together 3. However, when welding the ends of the multi-layer sections with butt joints the seams on the total cross section (thickness) of the joining elements make it difficult to assemble, weld and inspect the welded joints; considerable volume of welding works and the level of residual welding stresses, which ultimately impairs the performance and reliability of the design. When welding the ends of multilayer sections with each other, the stitches arranged in a staggered order require the manufacture of additional elements-inserts, which increases the number of different sizes of blanks transported to the place of installation and the difficulty of assembling and assembling at the installation; special devices are required to press down the insert elements, which causes a significant amount of discontinuities (gaps) in the places where the elements are connected to each other and deteriorates the reliability and performance of the structure. In addition, due to the considerable loss of time for the installation of inserts, their pressing, the mechanical stripping of each layer of the joint, the total time for assembling and welding of the installation and the installation cycle of installations are increased. The aim of the invention is to increase productivity by reducing the time spent on assembly and welding work during installation and to improve the reliability of the product. This goal is achieved by the fact that when assembling multilayer sections, some of the layers are shifted relatively to the others with the formation of ledges along the welded ends. Here, before welding, the ends of the multilayer sections are melted, and during assembly, some of the layers are shifted relative to the rest in two mutually perpendicular directions. This method allows the use of existing production reserves, simplify and reduce the amount of technological operations on installation in the construction conditions, improve the quality, performance and reliability of the structure. FIG. 1 shows the pressure vessel body, general view; FIG. 2 (a, b, c) - multi-layered sections with various options for sweeping the ends in the section; in fig. 3 is a diagram of preparing the ends of the section for welding; 4 shows a welded multilayer joint with displaced seam, section. The size of the sections constituting the building is chosen taking into account the possibility of their transportation by conventional means, for example, rail transport. Each section for both cylindrical parts and bottoms is assembled to the required thickness from relatively thin metal sheets by placing them on top of each other. The size of the preforms, the elements forming the multi-layer section, are set in length and width by the known methods of dividing a circle or sphere by shapes and can vary depending on the position in the section. In order to form a two-sided preparation of the edges for welding with offset ends in each section, a certain amount of layers are preliminarily shifted along the plane of their abutment. The magnitude of the displacement With a certain number of layers of SL in the section is set somewhat larger than the area of possible destruction of the multilayer body. According to tests on the destruction of multilayer structures, this area is within / j 6 °. The number of displaced layers and joined sections (where d is the thickness of the sheets that make up the section is determined from the condition of providing simplicity and ease of assembly and welding under installation conditions and can be varied. After assembling the sections, they are bent along the radius of curvature of the vessel, and then the ends of the MULTILAYER sections are melted. The height of the deposited layer dj (depends on the subsequent types and methods of welding the multilayer elements to each other. If necessary These ends of the multilayer sections are mechanically machined for welding. After the control assembly of the parts that make up the hull, in factory conditions, the sections are marked, the structure is disassembled and transported in separate sections to the construction site — installation. enlargement of sections (two-three and more) into blocks is carried out. Integration into blocks is carried out in a special tool of the type of lodgement by successive welding Heavens multilayer sections offset seams in the bottom position. The maximum size of the enlargement of elements into blocks is established, based on the convenience of installation and the capabilities of elevating vehicles, for example, up to half, tretinki, quarters, etc., forming one or another part of the vessel body (pipe). The final assembly of the structure is carried out from enlarged block elements directly at the installation site by welding the blocks between themselves using known methods. The required displacement of the ends in the section can be obtained before or after the operation to give the elements the required curvature by known deformation methods. The proposed method has manufactured and tested experimental models of oversized multilayer structures of two types.

T type. A multilayer vessel with an internal diameter of 780 mm, a wall thickness of 24 mm (4 mm 6 layers), consisting of a cylindrical part (pipe) with a diameter of 780 mm, a length of 2000 mm, and spherical bottoms of 390 mm.

N type A spherical tank with an inner diameter of 1200 mm and a wall thickness of 24 mm (4 mm 6 layers), consisting of two hemispheres,

the cylindrical part of the vessel a (pipe) is made up of four homogeneous multilayer sections of the size YuOOx x 1250x24 mm with a displacement of three layers along the edges by 100 mm,

The spherical part — the bottom (of the reservoir, vessel) is composed of five homogeneous multilayer sections-segments of the corresponding size.

This method of fabricating super-sized structures from shear-to-the-shear multi-layer sections removes restrictions on transport conditions and allows the manufacture of high-pressure vessels of unlimited size with increased operational reliability; provides the possibility of using developed high-quality sheet steels of increased strength, reducing the weight and labor intensity of manufacturing; does not require development costs, the creation of special equipment and lifting vehicles, as well as the construction of specialized factories; completely excludes circular machining of elements of the body during its manufacture; allows the control assembly of the hull or part thereof in plant conditions; at least twice

compared with monolithic seams, reduce the amount of welding work at the installation and ensure the required quality control of the seams; allows you to shorten the manufacturing cycle of high pressure housings during installation.

Claims (3)

1. A method for manufacturing super-thin-walled multi-layer housings of high-pressure vessels and pipes, in which multi-layered sections are assembled from individual sheets, bend them along the radius of curvature of the vessel, and then weld 5 with each other, characterized in that, in order to increase productivity by reducing the time for assembly and assembly work during installation and to increase the reliability of the product, during assembly of multilayer sections, part 0 layers are shifted relative to the rest with the formation of ledges on the welded ends. 2. The method according to claim. 1, characterized in that before welding The 5 ends of the multilayer sections are melted. 3, a method according to claim 1, characterized in that during assembly, part of the layers are shifted relative to the others in two mutually perpendicular directions. Sources of information taken into account in the examination 1. US patent 2 .480, 369, CL.24-446, 5 1949. 2. USSR author's certificate number 341284, cl. B 21D 51/24, 1969. . 3. US patent ti 3052021. cl. 29-471-1, 1956 (prototype).