A concentric reducer welding tooling and its manufacturing method and usage method

Abstract

The present invention belongs to the technical field of pipe welding equipment, and particularly provides a welding tooling for concentric reducing pipes, its manufacturing method and usage method. It mainly includes a positioning plate. A first slot for placing a heat exchange pipe and a second slot for placing a transition joint are formed on the positioning plate along an axis. A notch part for a TIG welding part to extend into is formed on the positioning plate between the first slot and the second slot; the positioning plate is cut from the bottom end of the notch part to form a first positioning plate and a second positioning plate. The first positioning plate and the second positioning plate are relatively slidable and the sliding distance is adjustable. The first slot is arranged on the first positioning plate, and the second slot is arranged on the second positioning plate. The present invention can make the butt welding between concentric reducing pipes not limited by the length of the same-diameter pipe section, and can effectively ensure the welding quality between concentric reducing pipes, with simple and convenient operation.

Description

Technical Field

[0001] The present invention belongs to the technical field of tube welding equipment, and particularly relates to a welding fixture for concentric pipes with different diameters, a manufacturing method thereof, and a using method thereof. Background Art

[0002] In the prior art, in the butt welding operation of the transition joint and the heat exchange tube of the steam generator in a nuclear power project, automatic TIG welding without filler wire is usually adopted, as Figure 1 shown. In order to ensure the welding quality of the weld seam, after the heat exchange tube 1 and the transition joint 2 are welded and assembled, they need to have good centering accuracy, that is, the misalignment amount ≤ 0.05 mm; and the pipe end fitting degree and the axis levelness. In addition, the tungsten electrode 81 of the automatic TIG welding machine also needs to ensure high-precision centering with the center of the circumferential weld.

[0003] For the traditional tube centering auxiliary welding and assembly fixture, as Figure 2 shown, it mainly uses two cylindrical support shafts 11 and a triangular prism-shaped clamping block 12 to achieve the axis centering of the same-diameter pipes. That is, first, two same-diameter pipes are assembled and ensured to be in contact with the support shaft 11, and then the clamping block 12 is moved to press the same-diameter pipes, and the centering assembly of the same-diameter pipes is achieved through the three-point centering principle. However, there are the following limitations and disadvantages in this way:

[0004] 1. There are dimensional errors in the processing of the support shaft and the clamping block and precision errors in the assembly, and the error accumulation factor directly affects the dimensional accuracy of the tube centering;

[0005] 2. This kind of fixture can only provide the centering function for two same-diameter pipes and cannot achieve the centering of pipes with different diameters. When the length of the wide-diameter section of the transition joint is too short, the centering effect is poor or even the clamping requirement cannot be met;

[0006] 3. In the way of pressing through the clamping block, axial fine adjustment cannot be carried out between the pipe sections. When the length of the wide-diameter section of the transition joint is too short, the deviation of the center axis levelness or plumbness of the pipe is obvious;

[0007] 4. After the fixture is clamped, the tube butt joint area is blocked, which directly affects the installation and welding of the automatic TIG welding equipment. Summary of the Invention

[0008] In order to overcome the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a welding fixture for concentric pipes with different diameters, a manufacturing method thereof, and a using method thereof, so that the butt welding between concentric pipes with different diameters is not limited by the length of the same-diameter pipe sections, and the welding quality between concentric pipes with different diameters can be effectively ensured, and the operation is simple and convenient.

[0009] The technical solution adopted by the present invention to solve its technical problems is:

[0010] A concentric reducer welding tooling, comprising a positioning plate, wherein a first slot for placing a heat exchange tube and a second slot for placing a transition joint are formed on the positioning plate along a first axis, and a notch for a TIG welding part to extend into is formed on the positioning plate between the first slot and the second slot;

[0011] The positioning plate is cut from the bottom end of the notch to form a first positioning plate and a second positioning plate, the first positioning plate and the second positioning plate are relatively slidably arranged and the sliding distance is adjustable, the first slot is arranged on the first positioning plate, and the second slot is arranged on the second positioning plate.

[0012] Preferably, a pipe is formed on the positioning plate along a second axis, and after the positioning plate is cut, a first pipe section arranged on the first positioning plate and a second pipe section arranged on the second positioning plate are formed;

[0013] The first axis is parallel to the second axis, and a distance adjusting member is arranged inside the first pipe section and the second pipe section.

[0014] Preferably, the distance adjusting member is a compression bolt, one end of the compression bolt is rotatably arranged on the second pipe section, and the other end of the compression bolt is in threaded connection with the first pipe section; or,

[0015] One end of the compression bolt is rotatably arranged on the first pipe section, and the other end of the compression bolt is in threaded connection with the second pipe section.

[0016] Preferably, a plurality of sliding guide posts are arranged between the first positioning plate and the second positioning plate.

[0017] Preferably, both the first slot and the second slot are V-shaped slots;

[0018] A first pressing plate with adjustable position is arranged on the first positioning plate corresponding to the first slot, and a second pressing plate with adjustable position is arranged on the second positioning plate corresponding to the second slot.

[0019] Preferably, a clamping part for clamping and fixing by a clamping device is arranged on the first positioning plate and / or the second positioning plate.

[0020] A manufacturing method of a concentric reducer welding tooling, applicable to the above-mentioned concentric reducer welding tooling, comprises the following steps:

[0021] Processing a first slot for placing a heat exchange tube and a second slot for placing a transition joint on the same positioning plate along a first axis, and opening a notch on the positioning plate between the first slot and the second slot for a TIG welding part to extend into;

[0022] The positioning plate is cut from the bottom end of the notch to form a first positioning plate and a second positioning plate, and the first slot is arranged on the first positioning plate, and the second slot is arranged on the second positioning plate.

[0023] Furthermore, the method further comprises the following steps:

[0024] Before cutting the positioning plate, a pipeline is opened on the positioning plate along the second axis, and the first axis and the second axis are parallel to each other;

[0025] And after the positioning plate is cut, a first pipe section arranged on the first positioning plate and a second pipe section arranged on the second positioning plate are formed;

[0026] Matching distance adjusting members are inserted into the first pipe section and the second pipe section to form a relative sliding arrangement between the first positioning plate and the second positioning plate.

[0027] A method for using a concentric reducer welding tool, which is applicable to the concentric reducer welding tool described above, comprises the following steps:

[0028] Placing the heat exchange tube in the first slot, and adjusting the length of the heat exchange tube extending into the notch, and after adjustment, installing and fixing the heat exchange tube in the first slot;

[0029] Placing the smaller diameter section of the transition joint in the second slot, and adjusting the length of the welding end of the transition joint extending into the notch, and installing and fixing the transition joint in the second slot after adjustment;

[0030] The first positioning plate or the second positioning plate is fixedly installed, and the relative distance between the first positioning plate and the second positioning plate is adjusted so that a butt weld is formed between the heat exchange tube and the transition joint;

[0031] The TIG welding part is installed so that the reference surface of the TIG welding part is close to the side surface of the first positioning plate arranged in the notch part, so as to realize the centering of the tungsten electrode of the TIG welding part and the butt weld, and perform the welding operation.

[0032] Furthermore, the TIG welding part adopts a petal structure, and after the tungsten electrode of the TIG welding part and the butt weld are aligned, the petals of the TIG welding part are closed and installed.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. In this solution, a new structural form is proposed for the welding tooling of the concentric reducer. By first machining a first slot adapted to the heat exchange tube and a second slot adapted to the transition joint on an integral positioning plate, a higher concentricity can be achieved between the first slot and the second slot, and the machining accuracy consistency is higher. Thus, it effectively avoids the machining dimension errors and assembly errors existing in the multi-piece assembly structure in the prior art, effectively improves the butt joint accuracy between the welds, and ensures the welding quality.

[0035] 2. In this solution, the first slot and the second slot are cleverly set on the same positioning plate first. On the basis of effectively controlling the concentricity between the first slot and the second slot, the positioning plate is formed by cutting, so that the first slot and the second slot are respectively arranged on the first positioning plate and the second positioning plate. Thus, the first slot and the second slot can be respectively adapted to the heat exchange tube and the transition joint, that is, both the heat exchange tube and the transition joint can be clamped through their longer diameter-width sections, effectively avoiding the situation in the traditional technology where the clamping is unstable due to the too short length of the clamping end of the transition joint, and the clamping operation is more reliable. Moreover, in this structural form of this solution, the butt weld formed between the heat exchange tube and the transition joint is set in an exposed manner, which will not cause obstacles to the installation and processing of the TIG welding part, and the entire butt welding operation can be more convenient and accurate.

[0036] 3. In addition, the formation of the notch part in this solution can effectively control the perpendicularity between the axes of the first slot and the second slot and the side wall surface of the notch part, which is convenient for the subsequent installation and alignment of the TIG welding part. And between the first positioning plate and the second positioning plate formed by cutting the positioning block, they are arranged in a relatively sliding form, so that the heat exchange tube and the transition joint respectively installed on the first positioning plate and the second positioning plate can fine-tune the width of the butt weld by adjusting the relative position distance between the first positioning plate and the second positioning plate, which is further convenient for controlling the welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 It is a schematic structural diagram when the heat exchange tube and the transition joint are welded by a TIG welding part.

[0039] Figure 2 It is a schematic use structural diagram of the butt welding auxiliary tooling in the prior art.

[0040] Figure 3 This is a schematic structural diagram of the welding tooling of the present invention in the installed state.

[0041] Figure 4 This is a schematic side view structural diagram of the welded part of the present invention when installed on the positioning plate.

[0042] Figure 5 This is a schematic side view structural diagram of the present invention in the state with the pressure plate.

[0043] Figure 6 This is a schematic cross-sectional view structural diagram of the rotation setting end of the pressing bolt of the present invention.

[0044] Figure 7 This is a schematic structural diagram of the present invention when installed and fixed by the clamp device after removing the TIG welding part.

[0045] Wherein:

[0046] 1 - heat exchange tube, 11 - support shaft, 12 - clamping block, 2 - adapter joint;

[0047] 3 - first positioning plate, 31 - first slot, 32 - first pressure plate, 33 - first pipe section, 34 - clamping part;

[0048] 4 - second positioning plate, 41 - second slot, 42 - second pressure plate, 43 - second pipe section;

[0049] 5 - notch part;

[0050] 6 - pressing bolt, 61 - convex ring, 62 - first sleeve plate, 621 - first through hole, 63 - second sleeve plate, 631 - second through hole, 64 - sliding guide post;

[0051] 7 - clamp device, 8 - TIG welding part, 81 - tungsten electrode. Specific embodiments

[0052] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. In the following description, many specific details are set forth in order to fully understand the present invention. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention.

[0054] Embodiment 1

[0055] As Figure 3 - 7 shown, in this embodiment, a concentric reducer welding tooling is provided, which mainly includes a positioning plate as an integral structure. On the positioning plate, a first slot 31 for placing the heat exchange tube 1 and a second slot 41 for placing the transition joint 2 are opened along a first axis. A notch 5 for the TIG welding part to extend into is opened on the positioning plate between the first slot 31 and the second slot 41.

[0056] As a preferred solution, in this embodiment, both the first slot 31 and the second slot 41 are V-shaped slots, and on the basis of maintaining concentricity, the respective slot depths of the first slot 31 and the second slot 41 are adapted to the diameter-width values of the heat exchange tube 1 and the transition joint 2. By processing the positioning plate in the overall state, slot processing can be carried out on the positioning plate according to the assembly diameter-width dimensions of the heat exchange tube 1 and the transition joint 2 that need to be butt-welded, and the dimensional consistency is better.

[0057] Furthermore, the positioning plate is cut from the bottom end of the notch 5 to form a first positioning plate 3 and a second positioning plate 4. The first positioning plate 3 and the second positioning plate 4 are relatively slidably arranged and the sliding distance is adjustable. The first slot 31 is arranged on the first positioning plate 3, and the second slot 41 is arranged on the second positioning plate 4. As a preferred solution, in this embodiment, a first pressing plate 32 with adjustable position is arranged on the first positioning plate 3 corresponding to the first slot 31, and a second pressing plate 42 with adjustable position is arranged on the second positioning plate 4 corresponding to the second slot 41. The first pressing plate 32 and the second pressing plate 42 are respectively arranged on the first positioning plate 3 and the second positioning plate 4 through bolt members. The installation and fixation of the heat exchange tube 1 are formed between the first pressing plate 32 and the first slot 31, and the installation and fixation of the transition joint 2 are formed between the second pressing plate 42 and the second slot 41.

[0058] In addition, a pipe is provided on the positioning plate along a second axis, and the second axis is parallel to the first axis. After the positioning plate is cut, the pipe forms a first pipe section 33 provided on the first positioning plate 3 and a second pipe section 43 provided on the second positioning plate 4. A distance adjusting member is inserted through the first pipe section 33 and the second pipe section 43. By adjusting the distance adjusting member, the relative position distance between the first positioning plate 3 and the second positioning plate 4 can be adjusted. Similarly, the pipe is processed in the overall state of the positioning plate, which has better machining dimension consistency.

[0059] As a preferred solution, the distance adjusting member in this embodiment is set as a compression bolt 6. One end of the compression bolt 6 is rotatably arranged on the second pipe section 43, and the other end of the compression bolt 6 is threadedly connected to the first pipe section 33. In actual application, one end of the compression bolt 6 can also be rotatably arranged on the first pipe section 33, and the other end of the compression bolt 6 can be threadedly connected to the second pipe section 43. The specific setting method will not be elaborated here.

[0060] Furthermore, in this embodiment, a ring 61 is provided on the outer periphery of the end of the compression bolt 6 for rotatable arrangement. A first sleeve plate 62 and a second sleeve plate 63 are provided corresponding to the ring 61. A first through hole 621 is provided in the first sleeve plate 62 corresponding to the ring 61, and the width value of the first through hole 621 is not less than the width value of the ring 61. A second through hole 631 is provided in the second sleeve plate 63 corresponding to the ring 61, and the width value of the second through hole 631 is not greater than the width value of the ring 61 and not less than the width value of the compression bolt 6. The compression bolt 6 is fixedly installed on the mounting plate through the second sleeve plate 63 and the first sleeve plate 62 in sequence to realize the rotatable arrangement of the compression bolt 6. In actual application, the structure of the first through hole 621 can also be directly provided on the mounting plate, that is, a counterbore is provided at the port of the pipe. At this time, only the second sleeve plate 63 needs to be provided to form the rotatable arrangement of the compression bolt 6. The specific structure will not be elaborated here.

[0061] As a preferred solution, a plurality of sliding guide posts 64 are provided between the first positioning plate 3 and the second positioning plate 4 corresponding to the compression bolt 6. The axes of the plurality of sliding guide posts 64 are parallel to the second axis to further ensure the operation stability and reliability when the heat exchange tube 1 is docked with the transition joint 2.

[0062] In addition, a clamping portion 34 for clamping and fixing by the clamping device 7 is further provided on the first positioning plate 3 and / or the second positioning plate 4. The clamping device 7 can be a bench vice with an anvil for facilitating the installation and fixing of the entire tooling.

[0063] For the convenience of further understanding of this solution, in this embodiment, a manufacturing method of a concentric reducer welding tooling is also provided, which is applicable to the above-mentioned concentric reducer welding tooling and mainly includes the following steps:

[0064] S10. Process a first slot 31 for placing the heat exchange tube 1 and a second slot 41 for placing the transition joint 2 along a first axis on the same positioning plate, so that the first slot 31 and the second slot 41 have the same coaxial axis; wherein, the cross-sections of the first slot 31 and the second slot 41 are both V-shaped; as one implementation manner, set the vertical distance from the axis line of the first slot 31 to its slot wall to be consistent with the radius value of the heat exchange tube 1, and set the vertical distance from the axis line of the second slot 41 to its slot wall to be consistent with the radius value of the smaller diameter section of the transition joint 2. At this time, the V-shaped angle of the slot is 90°, and the first axis lies on the surface of the positioning plate.

[0065] S20. Open a notch 5 on the positioning plate between the first slot 31 and the second slot 41 for the TIG welding portion 8 to extend into; wherein, the notch 5 is U-shaped, including two side walls arranged relatively parallel, and its side walls are perpendicular to the first axis.

[0066] S30. Open a pipeline on the positioning plate along a second axis, where the second axis is arranged parallel to the first axis.

[0067] S40. Cut the positioning plate from the bottom end of the notch 5 to form a first positioning plate 3 and a second positioning plate 4, and make the first slot 31 be arranged on the first positioning plate 3 and the second slot 41 be arranged on the second positioning plate 4; at the same time, form a first pipe section 33 arranged on the first positioning plate 3 and a second pipe section 43 arranged on the second positioning plate 4.

[0068] S50. Insert a distance adjusting member adapted to the first pipe section 33 and the second pipe section 43 to form a relative sliding setting between the first positioning plate 3 and the second positioning plate 4; in this embodiment, that is, by setting the compression bolt 6 and adjusting the threaded connection state between the compression bolt 6 and the first positioning plate 3 to adjust the distance between the first positioning plate 3 and the second positioning plate 4.

[0069] In addition, this embodiment also provides a method for using a concentric reducer welding tool, which is applicable to the concentric reducer welding tool described above and mainly includes the following steps:

[0070] S60. Place the heat exchange tube 1 in the first slot 31 and adjust the length of the heat exchange tube 1 extending into the notch 5. After adjustment, tighten the bolts on the first pressure plate 32 to install and fix the heat exchange tube 1 in the first slot 31.

[0071] S70. Place the smaller diameter section of the transition joint 2 in the second slot 41, and adjust the length of the welding end of the transition joint 2 extending into the notch 5. After adjustment, tighten the bolts on the second pressure plate 42 to install and fix the transition joint 2 in the second slot 41.

[0072] S80. The first positioning plate 3 or the second positioning plate 4 is fixedly installed by the clamping device 7. In this embodiment, only one of the first positioning plate 3 or the second positioning plate 4 is fastened and clamped.

[0073] S90. Adjust the relative distance between the first positioning plate 3 and the second positioning plate 4 so that a butt weld is formed between the heat exchange tube 1 and the transition joint 2; at this time, it should be noted that lubricating oil needs to be applied to several of the sliding guide pillars 64 to reduce the wear generated during the sliding process, extend the service life of the tooling, and ensure the assembly accuracy of the tooling during use.

[0074] S100. Install the TIG welding part 8, and make the reference surface of the TIG welding part 8 close to the side of the first positioning plate 3 set in the notch part 5, so as to realize the alignment of the tungsten electrode 81 of the TIG welding part 8 and the butt weld. Furthermore, the TIG welding part adopts a petal structure, so that the alignment operation of the tungsten electrode 81 of the TIG welding part 8 and the butt weld can be more intuitive. After the alignment of the tungsten electrode 81 of the TIG welding part 8 and the butt weld is realized, the petals of the TIG welding part 8 are closed and installed, and the welding operation is performed.

[0075] After welding is completed, remove the welded workpiece and repeat the above steps to perform the butt welding operation on the next welded part. In the practical process, this solution has been successfully applied in the butt welding of 690 alloy heat exchange tubes of a steam generator in a certain project. And it has been proved in practice that by adopting this technical solution, the assembly accuracy of the butt welding of concentric reducers can be greatly improved. The concentricity deviation can be controlled within 0.05 mm, the alignment deviation between the tungsten electrode of the automatic TIG welding equipment and the butt weld is within 0.1 mm, and the butt joint surface of the heat exchange tube 1 and the transition joint 2 is completely fitted. The horizontal degree of the tube center axis can be controlled within 0.5 mm. Compared with the traditional technical means, the weld qualification rate of the butt welding of 690 alloy heat exchange tubes is increased by more than 30%.

[0076] In this embodiment, the specific structural form of the TIG welding equipment can refer to the prior art and will not be elaborated here.

[0077] The above is only a preferred embodiment of the present invention, and it does not impose any form of limitation on the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A concentric reducer welding tooling, characterized in that It comprises a positioning plate, wherein a first slot for placing a heat exchange tube and a second slot for placing a transition joint are formed on the positioning plate along a first axis, and a notch for a TIG welding part to extend into is formed on the positioning plate between the first slot and the second slot; The positioning plate is cut from the bottom end of the notch to form a first positioning plate and a second positioning plate, the first positioning plate and the second positioning plate are arranged to slide relative to each other and the sliding distance is adjustable, the first slot is arranged on the first positioning plate, and the second slot is arranged on the second positioning plate; the first positioning plate and / or the second positioning plate are provided with a clamping portion for clamping and fixing by a clamping device; The notch is U-shaped and includes two side walls that are relatively parallel to each other, and the two side walls are perpendicular to the first axis; a pipe is opened on the positioning plate along the second axis, and after the pipe is cut from the positioning plate, a first pipe section is formed on the first positioning plate and a second pipe section is formed on the second positioning plate; the first axis and the second axis are parallel to each other, and a distance adjusting member is inserted into the first pipe section and the second pipe section; During production, a first slot for placing the heat exchange tube and a second slot for placing the transition joint are first processed on the same positioning plate along the first axis, and a notch is opened on the positioning plate between the first slot and the second slot for the TIG welding part to be inserted and set. Then, the positioning plate is cut from the bottom end of the notch to form a first positioning plate and a second positioning plate, and the first slot is set on the first positioning plate and the second slot is set on the second positioning plate.

2. The concentric reducer welding tooling according to claim 1, characterized in that The distance adjusting member is a clamping bolt, one end of which is rotatably disposed on the second pipe section, and the other end of which is threadedly connected to the first pipe section; or, One end of the clamping bolt is rotatably disposed on the first pipe section, and the other end of the clamping bolt is threadedly connected to the second pipe section.

3. A concentric reducer welding tooling according to any one of claims 1-2, characterized in that A plurality of sliding guide pillars are arranged between the first positioning plate and the second positioning plate.

4. A concentric reducer welding tooling according to claim 1, characterized in that, A first pressure plate with adjustable position is arranged on the first positioning plate corresponding to the first slot, and a second pressure plate with adjustable position is arranged on the second positioning plate corresponding to the second slot.

5. The concentric reducer welding tooling according to claim 1, characterized in that The following steps are also included: Before cutting the positioning plate, a pipeline is opened on the positioning plate along the second axis, and the first axis and the second axis are parallel to each other, so that after the positioning plate is cut, a first pipe section arranged on the first positioning plate and a second pipe section arranged on the second positioning plate are formed; Matching distance adjusting members are inserted into the first pipe section and the second pipe section to form a relative sliding arrangement between the first positioning plate and the second positioning plate.

6. A method for using a welding tooling for concentric reducing pipes, applicable to the welding tooling for concentric reducing pipes according to any one of the above-mentioned claims 1-5, characterized in that, The following steps are involved: Placing the heat exchange tube in the first slot, and adjusting the length of the heat exchange tube extending into the notch, and after adjustment, installing and fixing the heat exchange tube in the first slot; Placing the smaller diameter section of the transition joint in the second slot, and adjusting the length of the welding end of the transition joint extending into the notch, and installing and fixing the transition joint in the second slot after adjustment; The first positioning plate or the second positioning plate is fixedly installed, and the relative distance between the first positioning plate and the second positioning plate is adjusted so that a butt weld is formed between the heat exchange tube and the transition joint; The TIG welding part is installed so that the reference surface of the TIG welding part is close to the side surface of the first positioning plate arranged in the notch part, so as to realize the centering of the tungsten electrode of the TIG welding part and the butt weld, and perform the welding operation.

7. The method for using a welding tool for concentric pipes with different diameters according to claim 6, characterized in that The TIG welding part adopts a petal structure. After the tungsten electrode of the TIG welding part and the butt weld are aligned, the petals of the TIG welding part are closed and installed.

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