A leak detection tool for single heat exchange tube head before tube box welding

Abstract

The utility model discloses a kind of leak detection toolings for single heat exchange pipe tube head before pipe box welding, belong to heat exchanger equipment detection technical field;Including connecting section and symmetrically arranged lug section, connecting section middle part is equipped with fastening bolt, and its lower end is connected with elastic sealing body;One end of lug section is fixed positioning plate, and the other end is screwed with positioning bolt, for quick installation positioning.Sealing body is cylindrical structure, opening end is equipped with annular sealing surface and circumferential conical groove, under bolt pressurization, it can be self-adapting to fit heat exchange pipe tube head end face, form double seal;Sealing body side wall is equipped with pressure detection interface, for injecting detection medium and real-time monitoring pressure change, accurately positioning leakage point.The utility model is through elastic sealing, adjustable positioning and pressure detection function, realizes the unique leak detection of single heat exchange pipe, solves the problem that traditional overall detection cannot accurately position and repair, significantly reduces resource waste and quality risk, with the advantages of simple operation, reliable sealing, strong universality etc.

Description

Technical Field

[0001] This utility model relates to the field of heat exchanger equipment testing technology, and in particular to a leak testing fixture for the head of a single heat exchange tube before tube box welding. Background Technology

[0002] Heat exchangers with tube boxes are widely used in industry, but their manufacturing and assembly have long faced technical challenges. In traditional processes, after the air cooler tube bundle has completed pressure testing, the tube box cannot be disassembled due to structural limitations. Furthermore, during the assembly of the finned tubes and before the tube box is welded, it is impossible to effectively test for leaks at the welded joints of individual heat exchange tubes. If a leak occurs at the tube joint during subsequent operation, the leak cannot be repaired because the tube box is not removable, necessitating replacement or scrapping of the entire unit, resulting in significant resource waste and economic losses.

[0003] In the existing technology, conventional leak testing methods usually rely on the overall tube box sealing test, lacking an independent testing tool for individual heat exchange tubes. However, the overall tube box sealing test is difficult to accurately locate potential leak points, and local repairs cannot be performed after the tube box is welded, which exposes manufacturers to high quality risks.

[0004] Therefore, there is an urgent need for a lightweight, flexible and easy-to-operate leak testing fixture that can inspect each heat exchange tube individually before welding the tube box, ensuring welding quality and eliminating potential leaks at the source. Utility Model Content

[0005] This invention addresses the problem of the inability to independently test for leaks at the ends of individual heat exchange tubes before tube box welding, by providing a leak-testing fixture for individual heat exchange tube ends before tube box welding. Through an elastic sealing structure, adjustable positioning components, and pressure detection function, it enables precise sealing and leak testing of each heat exchange tube end before tube box welding, eliminating potential leaks at the source and reducing quality risks and resource waste for manufacturers.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A leak testing fixture for a single heat exchanger tube head before tube box welding is characterized by comprising a connecting section and an ear plate section. The connecting section has a threaded through hole in the middle, and a fastening bolt is screwed into the threaded through hole. The lower end of the fastening bolt is connected to a sealing body made of elastic material. The ear plate section has a pair, symmetrically arranged at both ends of the connecting section and perpendicularly connected to the connecting section. The end of one ear plate section is vertically fixed with a positioning plate, and the end of the other ear plate section is screwed with a positioning bolt. The sealing body has a cylindrical structure, with one end closed and coaxially fixed with the lower end of the fastening bolt, and the other end open to form an annular sealing surface that presses against the end face of the heat exchanger tube head.

[0008] Furthermore, a pressure detection interface is provided on the side wall of the sealing body, and the pressure detection interface is connected to the inner cavity of the sealing body.

[0009] Furthermore, the opening end face of the sealing body is provided with a tapered groove along the circumferential direction.

[0010] The beneficial effects of this utility model are:

[0011] The beneficial effects of this utility model lie in its effective solution to the problem of leak testing of individual heat exchanger tube ends before tube box welding through structural design. The fixture uses a sealing body made of elastic material, which, in conjunction with fastening bolts, forms an annular sealing surface that tightly fits the end face of the heat exchanger tube end. Combined with the pressure testing interface on the side wall, it enables independent leak testing of individual heat exchanger tubes and precise location of leak points, significantly improving testing efficiency and reliability. The symmetrically arranged adjustable positioning plates and positioning bolts on the ear plate section, along with the U-shaped clamp fixing method, make the fixture installation process simple and quick, allowing for stable fixation to the tube sheet without the need for special tools, greatly reducing operational complexity and time costs. The conical groove at the opening end of the sealing body can adapt to different tube diameters and end face conditions under bolt pressure, forming a double sealing structure that effectively prevents leakage of the testing medium and ensures high airtightness during the leak testing process. Furthermore, this fixture adopts a modular design, with replaceable key components, a robust and durable structure, and is suitable for various models and materials of tube box heat exchangers, offering strong versatility and low long-term operating costs. By checking each tube for potential leaks before welding, the scrapping problem caused by leakage of the entire tube bundle in the traditional process is avoided, significantly reducing resource waste and economic losses, and providing production enterprises with an efficient, economical and sustainable solution. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall assembly structure of this utility model;

[0013] Figure 2 This is a cross-sectional structural diagram of the sealing body of this utility model;

[0014] Figure 3 This is a schematic diagram of the structure of the present invention in the detection state;

[0015] In the diagram: 1. Connecting section; 2. Ear plate section; 3. Fastening bolt; 4. Sealing body; 5. Positioning plate; 6. Positioning bolt; 7. Pressure detection interface; 8. Conical groove; 9. Tube sheet; 10. Tube head. Detailed Implementation

[0016] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings, so that those skilled in the art can fully understand the technical solution and protection scope of this utility model. This embodiment is for illustrative purposes only and does not constitute a limitation of this utility model.

[0017] like Figure 1 , 2 As shown, this utility model provides a leak-testing fixture for the end of a single heat exchanger tube before welding a tube box. It includes a connecting section 1 and an ear plate section 2. The connecting section 1 has a threaded through hole in its middle, and a fastening bolt 3 is screwed into the threaded through hole. The lower end of the fastening bolt 3 (i.e., the end facing the heat exchanger tube end) is threadedly connected to a sealing body 4 made of elastic material. There are a pair of ear plate sections 2, symmetrically arranged at both ends of the connecting section 1 and perpendicularly connected to it, to provide stable support and fixation. The ear plate section 2 and the connecting section 1 can be an integral bent structure, or they can be fixed by welding, bolting, or other methods. A positioning plate 5 is vertically fixed to the end of one ear plate section 2, and the positioning plate 5 contacts the outer surface of the tube sheet 9, restricting the axial movement of the fixture. On the other side, the end of the 2 ear plate section is screwed with a positioning bolt 6. By adjusting the extension length of the positioning bolt 6, the position of the tooling can be further fixed. The sealing body 4 is a cylindrical structure. One end is closed and coaxially fixed with the lower end of the fastening bolt 3 to ensure that the pressure of the fastening bolt 3 can be evenly transmitted to the sealing body 4. The other end is open to form an annular sealing surface that is pressed against the end face of the heat exchange tube head 10. The material of the sealing body 4 can be selected from materials with good elasticity and resistance to media corrosion, such as nitrile rubber, silicone rubber, and polyurethane, to ensure the sealing effect and service life.

[0018] The sealing body 4 has a pressure detection interface 7 on its side wall. The pressure detection interface 7 is a threaded hole used to connect pressure gauges, pressure sensors, or air pumps, etc. The pressure detection interface 7 communicates with the inner cavity of the sealing body 4, allowing direct detection of pressure changes inside the sealing body 4. Compressed air, nitrogen, or other inert gases, as well as water or other liquids, can be introduced into the sealed space through the pressure detection interface 7. Real-time monitoring of pressure changes inside the sealing body 4 allows for the determination of whether a leak exists. The open end face of the sealing body 4 has a conical groove 8 circumferentially formed. The design of the conical groove 8 allows the sealing body 4 to better fit the end face of the heat exchange tube head 10 under the pressure of the fastening bolts 3, forming a double-sealing structure, effectively preventing leakage of the detection medium and ensuring high tightness during the leak test. The depth of the conical groove 8 can be adjusted according to the surface roughness of the heat exchange tube head 10 to obtain the best sealing effect.

[0019] like Figure 3 As shown, during use, the fixture is fixed to the tube sheet 9 by the positioning plate 5 and positioning bolts 6 of the ear plate section 2. The positioning plate 5 provides initial positioning support, and the positioning bolts 6 ensure a stable connection between the fixture and the tube sheet 9 by adjusting the bolt length. After installation, the fastening bolt 3 is rotated, and the elastic sealing body 4 connected to its lower end moves downward along the axial direction. The annular sealing surface of the opening end of the sealing body 4 presses against the end face of the heat exchange tube head 10 to form a sealed detection chamber.

[0020] The cylindrical structure of the sealing body 4 and the circumferential conical groove 8 at the open end undergo radial elastic deformation under bolt pressure, tightly fitting the end face of the pipe head 10. This adapts to different pipe diameters and end face machining errors, achieving a dual dynamic seal. Water or gas, or other detection media, are injected into the sealed cavity through the pressure detection port 7 on the side wall of the sealing body 4, and pressure changes are monitored in real time. If the pressure value is stable, it indicates no leakage at the weld of the pipe head 10; if the pressure drops, the location of the leak can be further confirmed by adjusting the tightening force of the fastening bolt 3 after depressurization or by checking the condition of the sealing body 4. After the test is completed, the fastening bolt 3 is loosened, the sealing body 4 elastically resets, and the fixture can be quickly disassembled and transferred to the next pipe head 10 to be tested, achieving efficient leak testing for each pipe.

Claims

1. A leak testing fixture for the end of a single heat exchanger tube before welding a tube box, characterized in that: The device includes a connecting section (1) and an ear plate section (2). The connecting section (1) has a threaded through hole in the middle, and a fastening bolt (3) is screwed into the threaded through hole. The lower end of the fastening bolt (3) is connected to a sealing body (4) made of elastic material. The ear plate section (2) has a pair, which are symmetrically arranged at both ends of the connecting section (1) and perpendicularly connected to the connecting section. The end of one ear plate section is vertically fixed with a positioning plate (5), and the end of the other ear plate section is screwed with a positioning bolt (6). The sealing body (4) is a cylindrical structure. One end of the sealing body is closed and coaxially fixed with the lower end of the fastening bolt (3), and the other end is open to form an annular sealing surface that is pressed against the end face of the heat exchange tube.

2. The leak testing fixture for a single heat exchanger tube head before tube box welding as described in claim 1, characterized in that: The sealing body (4) has a pressure detection interface (7) on its side wall, and the pressure detection interface (7) is connected to the inner cavity of the sealing body (4).

3. The leak testing fixture for a single heat exchanger tube head before tube box welding as described in claim 1, characterized in that: The sealing body (4) has a tapered groove (8) circumferentially formed on the end face of the opening.

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