Double-wall pipe centering device

Abstract

The invention discloses a double-wall pipe centering device which comprises an upper clamp (1), a lower clamp (2), heavy nuts (3), a centering bolt (4) and a connecting nut (5), the upper clamp (1) and the lower clamp (2) are fixed to a double-wall pipe outer pipe (7) through the connecting nut (5), the heavy nuts (3) are symmetrically fixed to lugs of the upper clamp (1) and lugs of the lower clamp (2) respectively, the centering bolt (4) penetrates through the heavy nuts (3), and the upper clamp (1) and the lower clamp (2) are connected through the connecting nut (5). And the extending length can be adjusted through rotation in the heavy nut (3). According to the double-wall pipe centering device, the problems of difficulty in centering between the inner pipe and the outer pipe as well as between the outer pipes and poor concentricity in the double-wall pipe manufacturing period are solved, the double-wall pipe centering device is simple in structural form, convenient to operate and maintain and capable of being repeatedly used, labor hours are saved, the pipeline manufacturing precision is improved, and the risk of pipeline stress concentration is reduced.

Description

Technical Field

[0001] The invention relates to the field of manufacturing and installing double-walled ship pipes, and in particular to a double-walled pipe centering device. Background Art

[0002] In response to increasingly stringent carbon emission regulations, more and more newly built and modified ships are choosing to use LNG as a low-carbon / zero-carbon fuel in order to achieve the ultimate goal of zero greenhouse gas emissions from ships. According to the IGF specification, double-walled pipes are required for LNG fuel supply pipelines in the engine room. Double-walled pipes generally use stainless steel pipes with thinner walls, which are butt-welded as required. The manufacturing of double-walled pipes requires the welding, flaw detection and pressure testing of the inner pipe before the assembly and welding of the outer pipe. During this process, it is difficult to align the inner and outer pipes and the outer pipes. The concentricity is poor after welding. The use of horse plates for positioning and adjustment wastes manpower and damages the parent material. It is also easy to cause local stress concentration in the pipeline, causing unnecessary system leakage risks. Summary of the invention

[0003] The purpose of the present invention is to provide a double-walled pipe centering device which can solve the problems of difficulty in centering and poor concentricity between inner pipe and outer pipe, outer pipe and outer pipe during the production of double-walled pipes.

[0004] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: a double-walled pipe centering device, comprising an upper clamp (1), a lower clamp (2), a heavy nut (3), a centering bolt (4) and a connecting nut (5), wherein the upper clamp (1) and the lower clamp (2) are fixed to an outer tube (7) of the double-walled pipe via the connecting nut (5), the heavy nut (3) is symmetrically fixed to the lugs of the upper clamp (1) and the lower clamp (2), respectively, and the centering bolt (4) passes through the heavy nut (3) and can be adjusted in length by rotating in the heavy nut (3).

[0005] There are four heavy nuts (3), two of which are respectively installed on the lugs of the upper clamp (1) and the lower clamp (2).

[0006] There are four centering bolts (4).

[0007] The invention discloses a double-wall pipe centering device, which solves the problems of difficulty in centering inner pipe and outer pipe, outer pipe and outer pipe during the production of double-wall pipes, and poor concentricity. The device has a simple structure, is easy to operate and maintain, and can be reused, thus saving man-hours, improving the production accuracy of pipelines, and reducing the risk of stress concentration in pipelines. The device can replace horse plates for centering double-wall pipes, reducing a series of auxiliary work such as welding, adjustment, cutting, grinding, and surface treatment of horse plates, and does not damage parent materials. The device can be installed and disassembled by bolts, has no loss in use, and can be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a schematic diagram of the structure of a double-wall pipe centering device of the present invention. Figure 1 .

[0009] Figure 2 This is a schematic diagram of the structure of a double-wall pipe centering device of the present invention. Figure 2 .

[0010] Figure 3 This is a schematic diagram of the structure of a double-wall pipe centering device of the present invention. Figure 3 .

[0011] Figure 4 It is an exploded schematic diagram of a double-wall pipe centering device of the present invention.

[0012] In the figure: 1. upper clamp; 2. lower clamp; 3. heavy nut; 4. centering bolt; 5. connecting nut; 6. double-walled inner tube; 7. double-walled outer tube. DETAILED DESCRIPTION

[0013] like Figures 1 to 4 As shown, the double-wall pipe centering device comprises an upper clamp 1, a lower clamp 2, four heavy nuts 3, four centering bolts 4 and a connecting nut 5. The upper clamp 1 and the lower clamp 2 are fixed to the outer tube 7 of the double-wall pipe through the connecting nut 5. The heavy nuts 3 are symmetrically fixed on the lugs of the upper clamp 1 and the lower clamp 2, respectively. Two are installed on the lugs of the upper clamp 1 and the lower clamp 2, respectively. The centering bolt 4 passes through the heavy nut 3 and can be adjusted in length by rotating in the heavy nut 3. When using the tooling, the upper clamp 1 and the lower clamp 2 can be fixed to the outer tube 7 of the double-wall pipe through the connecting bolt 5. By adjusting the extended length of the centering bolt 4, the inner tube 6 of the double-wall pipe or the double-wall pipe can be adjusted in multiple directions of the circumferential cross section. The relative position of the outer tube 7 reaches the concentricity that meets the technical requirements, and the double-walled tube inner tube 6 and the double-walled tube outer tube 7 are fixed at the same time. After the welding work is completed, the centering bolt 4 and the connecting bolt 5 can be rotated in the opposite direction to remove the centering device for use in the lower section of the pipeline. The double-walled tube centering device of the present invention can adjust the relative position of the inner tube or the outer tube in multiple directions of the circumferential cross-section by adjusting the extended length of the centering bolt, so that the concentricity between the double-walled tube inner tube and the double-walled tube outer tube or the double-walled tube outer tube and the double-walled tube outer tube meets the specified technical requirements, and plays a role in adjusting and fixing the position of the inner and outer tubes; thereby improving the manufacturing accuracy of the pipeline, without damaging the parent material, and reducing the risk of stress concentration in the pipeline after welding.

Claims

1. A double-wall pipe centering device, characterized in that: The invention comprises an upper clamp (1), a lower clamp (2), a heavy nut (3), a centering bolt (4) and a connecting nut (5); the upper clamp (1) and the lower clamp (2) are fixed to an outer tube (7) of a double-walled tube via a connecting nut (5); the heavy nut (3) is symmetrically fixed to the lugs of the upper clamp (1) and the lower clamp (2); the centering bolt (4) passes through the heavy nut (3) and can be adjusted in length by rotating in the heavy nut (3).

2. A double-wall pipe centering device according to claim 1, characterized in that: There are four heavy nuts (3), two of which are respectively installed on the lugs of the upper clamp (1) and the lower clamp (2).

3. A double-wall pipe centering device according to claim 1, characterized in that: There are four centering bolts (4).

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