Welded lining flange with special fixture and mounting method

Abstract

The invention discloses a welding lining flange with a special fixture and an installation method, the flange comprises a convex socket type flange joint, the convex socket type flange joint comprises a convex flange plate, a convex flange clamping boss, a convex flange lining pipe, a convex flange chamfer, a convex flange boss, a convex flange end sealing line end face, a convex flange end sealing line notch, an end sealing line and a concave socket type flange joint, the concave flange end sealing line device comprises a concave flange plate, a concave flange clamping boss, a concave flange lining pipe, a concave flange chamfer, a concave flange end sealing line end face, a concave flange end sealing line notch and a concave flange groove, and the special clamp comprises a static top plate, a clamp installation base, a movable top plate, a telescopic device and a clamp handle. And a combined body formed by the convex flange boss and the convex flange lining pipe is inserted into the concave flange groove. According to the flange, the problems of axial wriggling, loosening and falling of the lining pipeline can be solved, and the overall service life of the pipeline is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of pipeline connection workpieces, and more particularly, relates to a welding liner flange with a special fixture and an installation method. Background Art

[0002] Welded lined flanges are key pipe connectors and are widely used in chemical, petroleum, energy, metallurgy and other industrial fields. Their core function is to connect the pipe to the flange body by welding, and to isolate the metal matrix from the corrosion of corrosive media through the lining material, thereby extending the service life of the pipeline system and ensuring sealing. During its use, the ultra-high molecular lining pipe has insufficient adhesion and is prone to axial creep, which leads to loosening and falling off.

[0003] Traditional lined pipes have weak bonding with the metal matrix. Under long-term mechanical vibration and axial creep caused by medium erosion, the lined pipes can easily become loose and fall off. At the same time, corrosive media can also penetrate into the metal matrix, affecting the sealing performance. Summary of the Invention

[0004] In response to the above defects or improvement needs of the prior art, the present invention provides a welding liner flange and an installation method with a special clamp, which improves the sealing of the welded liner flange through the convex flange liner pipe and the concave flange liner pipe, optimizes the welding space through the convex flange chamfer and the concave flange chamfer, ensures uniform coverage of the weld, and solves the axial creep, looseness and falling off problems of the liner pipe by installing the end sealing line in the convex flange end sealing line slot and the concave flange end sealing line slot, thereby improving the overall service life of the pipe, and clamps the convex flange plate and the concave flange plate through the special clamp to ensure that each contact point is synchronously and evenly stressed during clamping and the internal connection is tight.

[0005] In order to achieve the above object, according to a first aspect of the present invention, there is provided a welding liner flange with a special fixture, comprising: A male and female flange joint comprises a male flange, a male flange clamping boss provided on the outside of the male flange, a male flange inner liner pipe which is in close contact with the inner wall of the male flange and folded over at the end, and a male flange boss provided on the lower middle part of the inner side of the male flange and protruding outwards; the vertical side surface of the male flange boss is the end face of the male flange end seal line; A female socket flange joint for embedding and connecting a male socket flange joint comprises a female flange plate, a female flange clamping boss provided on the outside of the female flange plate, a female flange inner liner pipe closely attached to the inner wall of the female flange plate and with its end folded over, and a female flange groove provided on the inner side of the female flange plate and inwardly recessed; the vertical side surface of the female flange groove is the end face of the female flange end seal line; And multiple special fixtures, which include a fixture mounting seat with a groove structure, a static top plate and a dynamic top plate arranged at both ends of the outer side of the groove structure of the fixture mounting seat; the dynamic top plate is connected to the groove structure through a telescopic device; the static top plate and the dynamic top plate respectively support the outer sides of the convex flange and the concave flange at both ends of the welded liner flange.

[0006] Furthermore, a clamp handle for holding is provided at the bottom of the clamp mounting seat.

[0007] Furthermore, the telescopic device adopts a horizontal jack.

[0008] Furthermore, a combination of the convex flange boss and the convex flange liner is inserted into the inner 1 / 2 to 1 / 4 of the concave flange groove to prevent hot melt welding slag medium from entering the lining layer.

[0009] Furthermore, a convex flange chamfer is provided at the upper inner end of the convex flange disk, a plurality of convex flange end sealing line grooves are provided on the end surface of the convex flange end sealing line, and an end sealing line is provided in the convex flange end sealing line groove; a concave flange chamfer is provided at the upper inner end of the concave flange disk, a plurality of concave flange end sealing line grooves are provided on the end surface of the concave flange end sealing line, and an end sealing line is provided in the concave flange end sealing line groove.

[0010] Furthermore, the static top plate and the dynamic top plate are both crescent-shaped, and the inner contours thereof coincide with the curvature of the outer contour of the flange boss.

[0011] According to a second aspect of the present invention, a method for installing a welded liner flange with a special fixture is provided, which is implemented using a welded liner flange with a special fixture, comprising: S100: Select pipes with male and female socket flanges as the connection objects. Align the axes of the flanges of the pipes to be connected. After the axes are aligned, slowly insert the male socket flange into the female socket flange. Maintain a constant speed during the insertion process to avoid damaging the flange sealing surface due to excessive insertion. S200: Use the telescopic device to adjust the distance between the static top plate and the dynamic top plate, and then use the special fixture to press the outer sides of the convex flange and the concave flange; S300: Adjust the telescopic device again, and use the telescopic device to lift the bracket to drive the movable top plate installed on it to move forward. The surface of the lifting bracket has been specially treated with a roughness of Ra ≤ 0.8μm to ensure good contact with the movable top plate. During the movement, ensure that each contact point is uniformly stressed during clamping, and at the same time ensure that the internal connection is tight. After the convex flange and the concave flange are clamped on one side, use at least another set of special clamps and follow the same operating procedures as above to clamp the other parts of the flange to ensure that the flange is evenly clamped all around to form a stable pre-tightened state; S400: Use flame-retardant glass fiber cloth to fill the gap between the male and female flanges. This flame-retardant glass fiber cloth has an oxygen index of ≥35% and is heat-resistant and flame-retardant. The glass fiber cloth must be tightly packed into the gap to ensure no gaps are left. This prevents welding fluid from leaking through the gap during subsequent welding, which could damage the inner wall of the pipe and affect its normal use and service life. S500: Adjust the welding machine current to a preset value. This setting value is based on parameters such as the pipe material, wall thickness, and flange specifications. Use a low-current, multiple-welding process. The single welding current is controlled at 80-120A. The welding length each time does not exceed 20mm. Adjacent welds must be spaced 5-10mm apart to reduce the heat-affected zone, welding deformation, and stress concentration.

[0012] Furthermore, a plurality of the special clamps are used in combination to ensure that each contact point is subjected to uniform force when the convex flange and the concave flange are clamped.

[0013] Furthermore, cooling measures need to be taken around the welding part, and the cooling measures include covering the non-welding contact area between the convex flange and the concave flange with a wet rag.

[0014] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art: 1. The welded liner flange of the present invention improves the sealing performance of the welded liner flange through the convex flange liner pipe and the concave flange liner pipe, optimizes the welding space through the convex flange chamfer and the concave flange chamfer, ensures uniform coverage of the weld, and solves the axial creep, looseness and falling problems of the liner pipe by installing the end sealing wire groove at the convex flange end and the concave flange end sealing wire groove, thereby improving the overall service life of the pipe. The convex flange plate and the concave flange plate are clamped by a special clamp to ensure that each contact point is synchronously and evenly stressed during clamping and the internal connection is tight.

[0015] 2. The welded liner flange of the present invention is connected to corresponding liner pipes on the convex flange clamping boss surfaces of the female socket flange joint and the male socket flange joint. The liner pipe serves as a protective layer, directly contacts the fluid medium, isolates the direct contact between corrosive substances and the flange, and improves the sealing performance of the welded liner flange.

[0016] 3. The welded liner flange of the present invention is provided with corresponding end sealing line notches on both the female socket-type flange joint and the male socket-type flange joint. The notches are opened on the end faces of the corresponding end sealing lines according to the design dimensions. Under the interaction of the six end sealing lines of the flange, the axial creep, loosening and falling problems of the liner pipe are solved, thereby improving the overall service life of the pipe. In addition, the sealing performance of the pipe can also be improved.

[0017] 4. The special fixture of the present invention rotates the telescopic device to control the distance between the static top plate installed on the fixture mounting seat and the dynamic top plate installed on the telescopic device, and then the special fixture is clamped into the convex flange and the concave flange, and the telescopic device is rotated to clamp the convex flange and the concave flange to ensure that each contact point is synchronously and evenly stressed during clamping and the internal connection is tight. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the construction of a welded liner flange according to an embodiment of the present invention; Figure 2 This is a partial view of the welded liner flange at point A according to an embodiment of the present invention; Figure 3 A half-section view of a male and female socket flange joint according to an embodiment of the present invention; Figure 4 This is a partial view of the male and female socket flange joint at position B according to an embodiment of the present invention; Figure 5 A half-section view of a female socket-and-spigot flange joint according to an embodiment of the present invention; Figure 6 This is a partial view of the female socket-type flange joint at position C according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of a special fixture according to an embodiment of the present invention; Figure 8 A half-section view of a welded liner flange according to an embodiment of the present invention; Figure 9 This is a partial view of the welded liner flange at position D according to an embodiment of the present invention; Figure 10 This is a construction flow chart of a welded liner flange according to an embodiment of the present invention.

[0019] In all the drawings, the same figure marks represent the same technical features, specifically: 1- convex socket type flange joint, 2- concave socket type flange joint, 3- special fixture, 11- convex flange plate, 12- convex flange clamping boss, 13- convex flange inner liner, 14- convex flange chamfer, 15- convex flange boss, 16- convex flange end sealing line end face, 17- convex flange end sealing line notch, 18- end sealing line, 21- concave flange plate, 22- concave flange clamping boss, 23- concave flange inner liner, 24- concave flange chamfer, 25- concave flange end sealing line end face, 26- concave flange end sealing line notch, 27- concave flange groove, 31- static top plate, 32- fixture mounting seat, 33- moving top plate, 34- telescopic device, 35- fixture handle. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0021] In the description of the embodiments of the present invention, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the product of the invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it should not be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0022] Furthermore, the use of terms such as "horizontal," "vertical," and "overhanging" does not necessarily imply that the component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0023] In the description of the embodiments of the present invention, "a plurality of" means at least two.

[0024] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0025] The embodiment of the present invention provides a welding liner flange with a special fixture. Figure 1 、 2As shown, it includes a male and female socket flange joint 1, a female socket flange joint 2 and a special fixture 3. After aligning the axes of the male and female socket flange joint 1 and the female socket flange joint 2, the male and female socket flange joint 1 is inserted into the female socket flange joint 2, and multiple special fixtures 3 are used to support the outer sides of the male flange plate 11 and the female flange plate 21 at both ends of the welded liner flange. The distance between the dynamic top plate 33 and the static top plate 31 is adjusted by the telescopic device 34, and the special fixture 3 is used to support the male and female socket flange joint 1 and the female socket flange joint 2 that have been connected. The outside of the flange, then adjust the telescopic device 34 to ensure that each contact point is evenly stressed when the flanges at both ends of the welded liner flange are clamped and the internal pipes are tightly connected. The convex socket flange joint 1 and the concave socket flange joint 2 are welded and fixed according to the welding process, and effective cooling measures are taken around the welding part to avoid adverse effects of excessive temperature on the lining pipe and flange. Specifically, physical methods such as damp rags can be used to cool down, and the damp rags can be covered on the non-welding contact area to keep the temperature of the area at a reasonable temperature.

[0026] Specifically, such as Figure 3 、 4As shown, the convex and socket flange joint 1 includes a convex flange plate 11, a convex flange clamping boss 12, a convex flange liner pipe 13, a convex flange chamfer 14, a convex flange boss 15, a convex flange end sealing line end face 16, a convex flange end sealing line notch 17 and an end sealing line 18. A convex flange clamping boss 12 is fixed on the outer side wall of the convex flange plate 11, and a convex flange liner pipe 13 is connected inside the convex flange plate 11 and the convex flange clamping boss 12. The inner end of the convex flange liner pipe 13 extends radially toward the outside of the convex flange end sealing line end face 16 to form an L-shaped edging structure. The convex flange liner pipe 13 adopts ultra-high molecular material, which can prevent the medium from entering the liner flange, thereby improving the corrosion resistance and sealing of the welded liner flange. A convex flange chamfer 14 is opened at the upper end of the inner side of the convex flange plate 11. The convex flange chamfer 14 can optimize the welding space and ensure the weld Uniform coverage, the convex flange boss 15 is arranged on the top of the convex flange disc 11, and the convex flange boss 15 arranged on the convex socket flange joint 1 is inserted into the concave flange groove 27 of the concave socket flange joint 2, thereby extending the medium leakage path, increasing the leakage resistance, and enhancing the sealing performance of the flange after welding. A convex flange end sealing line end face 16 is provided on the inner side of the convex flange disc 11, and three convex flange end sealing line notches 17 are opened in the middle and lower part of the convex flange end sealing line end face 16. The end sealing line 18 is arranged in the corresponding convex flange end sealing line notches 17. The end sealing line 18 is an elastic sealing ring. By adding multiple end sealing lines 18 (for example, 3 end sealing lines) to the flange end sealing line end face, the friction between the lining pipe and the end sealing line end face is increased, thereby solving the axial creep, loosening and falling off problems of the lining pipe, thereby improving the overall service life of the pipeline. The welded liner flange of the present invention has a convex flange liner pipe that isolates the medium from entering the flange joint, thereby improving the sealing of the welded liner flange, optimizing the welding space by chamfering the convex flange, ensuring uniform coverage of the weld, improving the welding quality of the flange connection, extending the medium leakage path by the convex flange boss, increasing leakage resistance, and enhancing the sealing of the flange after welding, improving the sealing of the flange by installing the end sealing line at the end sealing line groove of the convex flange, and solving the problems of axial creep, loosening and falling off of the liner pipe.

[0027] Specifically, such as Figure 5 、 6As shown, the female socket-type flange joint 2 includes a female flange plate 21, a female flange clamping boss 22, a female flange lining pipe 23, a female flange chamfer 24, a female flange end sealing line end face 25, a female flange end sealing line notch 26 and a female flange groove 27. A female flange lining pipe 23 is connected to the inside of the female flange plate 21 and the female flange clamping boss 22. The inner end of the female flange lining pipe 23 extends radially toward the outside of the female flange end sealing line end face 25 to form an L-shaped edging structure. The female flange lining pipe 23 adopts ultra-high molecular material, which can prevent the medium from entering the lining flange, thereby improving the corrosion resistance and sealing of the welded lining flange. A concave flange chamfer 24 is provided at the upper end, which can optimize the welding space and ensure uniform coverage of the weld. A concave flange end sealing line end face 25 is provided on the inner side of the concave flange plate 21, and three concave flange end sealing line notches 26 are provided in the middle and lower part of the concave flange end sealing line end face 25. The end sealing line 18 is placed in the corresponding concave flange end sealing line notches 26. The end sealing line 18 is an elastic sealing ring. By adding multiple end sealing lines 18 (for example, 3 end sealing lines) to the flange end sealing line end face, the friction between the lining pipe and the end sealing line end face is increased, thereby solving the problems of axial creep, loosening and falling off of the lining pipe, thereby improving the overall service life of the pipeline. In the welded lined flange of the present invention, the inner liner pipe of the concave flange enters the flange joint through the isolation medium, thereby improving the sealing of the welded lined flange, optimizing the welding space by chamfering the concave flange, ensuring uniform coverage of the weld, improving the welding quality of the flange connection, and improving the sealing of the flange by installing the end sealing line at the end sealing line notch of the concave flange, and solving the problems of axial creep, loosening and falling off of the lined pipe.

[0028] Specifically, such as Figure 1 、 7As shown, the special fixture 3 includes a static top plate 31, a fixture mounting seat 32, a dynamic top plate 33, a telescopic device 34 and a fixture handle 35. The special fixture 3 is made of high-strength alloy steel with a yield strength of not less than 800MPa, and has good deformation resistance and mechanical stability. The static top plate 31 is fixedly mounted on the fixture mounting seat 32, and its working surface in contact with the flange is precisely ground, and the curvature of the working surface matches the curvature of the outer contour of the flange boss. The dynamic top plate 33 is mounted on the jacking support of the horizontal spiral telescopic device 34. A telescopic device guide device is installed on the dynamic top plate 33 to ensure the stability and guidance of the dynamic top plate 33 during movement. The special fixture 3 is used to support the male socket-type flange joint 1 and the female socket-type flange joint that have been connected. The flange flange of the flange joint 2 first ensures that the static top plate 31 is against the flange flange of one side, and then the screw on the telescopic device 34 is rotated to adjust the gap between the dynamic top plate 33 and the static top plate 31, so as to achieve a close fit between the two flanges. A plurality of special fixtures 3 are used to ensure that each contact point is evenly stressed when the flanges at both ends of the welded liner flange are clamped and the internal pipes are tightly connected. The telescopic device 34 adopts a horizontal screw jack with a specification of 5 tons and 240mm. The special fixture 3 can automatically align the center line and has the characteristics of easy operation and compact size. It can also adjust the flange docking pressure according to the on-site construction conditions and control the weld gap of the flange contact. It is superior to previous generation tools (such as pipe external adapters) in the actual construction operation of welding liner flanges. The special fixture of the present invention rotates the telescopic device to control the distance between the static top plate installed on the fixture mounting seat and the dynamic top plate installed on the telescopic device, and then the special fixture is clamped into the convex flange and the concave flange, and the telescopic device is rotated to clamp the convex flange and the concave flange to ensure that each contact point is synchronously and evenly stressed during clamping and the internal connection is tight.

[0029] For example, when using the special clamps 3, it's important to note that for smaller flanges, a set of special clamps can be placed at each end of the flange diameter, with the angle between the two sets of clamps being 180°. This ensures uniform force along the diameter during the clamping process. For larger flanges, it's recommended to use three or more sets of special clamps. In this case, these clamps should be evenly spaced along the circumference of the flange. If three sets of clamps are used, the angle between them should be 120°; if four sets are used, the angle should be 90°, and so on. When adjusting the telescopic device 34 for clamping, the telescopic devices on each special clamp must be adjusted synchronously. For example, by uniformly controlling the lifting stroke of each jack (if a horizontal jack is used for the telescopic device), each movable top plate 33 can approach the static top plate 31 at the same speed and displacement. This ensures that each contact point is uniformly stressed, ensuring a tight connection between the male and female flanges and a stable and reliable preload condition.

[0030] As a preferred solution, in some other embodiments, the vertical sides of the convex flange liner tube 13 and the concave flange liner tube 23 are both provided with a texture structure for increasing friction, and the texture structure includes a plurality of textures distributed along the axial and circumferential directions of the liner tube, and the texture is a rectangular texture with a texture depth of 0.1mm-0.5mm and a spacing between adjacent textures of 0.5mm-1mm, so as to effectively prevent the liner tube from moving in the axial and radial directions, enhance the bonding strength between the liner tube and the flange body, prevent the liner tube from loosening and falling off, and improve the overall sealing and service life of the pipeline.

[0031] As a preferred solution, in some other embodiments, the chamfer angles of the flange chamfer 14 and the concave flange chamfer 24 are 15°-50°, and the ends of the flange chamfer 14 and the concave flange chamfer 24 are also provided with a slight rounded transition, and the rounded radius is 0.5mm-1.5mm to avoid stress concentration.

[0032] As a preferred solution, in some other embodiments, a detachable wear-resistant liner is added to the working surface of the static top plate 31 and the dynamic top plate 33. The side of the wear-resistant liner in contact with the outer side of the flange adopts meshing teeth with a tooth depth of 0.3-0.8 mm. The wear-resistant liner and the top plate can be quickly replaced by bolt connection to adapt to flanges with different surface conditions and extend the service life of the fixture.

[0033] like Figure 8 As shown, after the male socket flange joint 1 is inserted into the female socket flange joint 2, the male flange boss enters one-third of the female socket flange joint 2 and leaves two-thirds of the space between the end face 25 of the female flange end seal line. The "fewer male and more female" welding liner flange design plays a role in preventing hot-melt welding slag medium from entering the lining layer.

[0034] like Figure 9 As shown, the end sealing line 18 is installed in the end sealing line groove 17 of the convex flange. The end sealing line 18 is an elastic sealing ring. By adding multiple end sealing lines 18 (for example, 3 end sealing lines) on the end face of the flange end sealing line, the friction between the convex flange liner pipe 13 and the convex flange end sealing line end face 16 is increased, thereby solving the axial creep, loosening and falling problems of the convex flange liner pipe 13, thereby improving the overall service life of the pipeline. The function of the end sealing line groove of the concave flange 26 is the same as that of the convex flange end sealing line groove 17.

[0035] like Figure 10 As shown, in another embodiment of the present invention, a method for installing a welded liner flange with a special fixture is provided, comprising the following steps: Select the pipes with male and female socket flange joints 1 and female socket flange joints 2 as the connection objects, align the axes of the flange joints of the pipes to be connected, and after completing the axis alignment, slowly insert the male and female socket flange joints 1 into the female socket flange joints 2. The insertion process needs to be maintained at a constant speed to avoid damage to the flange sealing surface due to too fast insertion.

[0036] The screw of the telescopic device 34 is rotated to adjust the distance between the static top plate 31 and the dynamic top plate 33 , and then the special fixture 3 is pressed against the outer sides of the convex flange 11 and the concave flange 21 .

[0037] Rotate the screw of the telescopic device 34 again, and use the telescopic device 34 to lift the bracket to drive the movable top plate 33 installed on it to move forward. The surface of the lifting bracket has been specially treated with a roughness of Ra≤0.8μm to ensure good contact with the movable top plate 33. During the movement, ensure that each contact point is synchronously and evenly stressed during clamping, and at the same time ensure that the internal connection is tight. After the convex flange 11 and the concave flange 21 are clamped on one side, use another set of special clamps 3 to clamp the other parts of the flange according to the same operating process as above to ensure that the flange is evenly clamped all around to form a stable pre-tightened state.

[0038] Use flame-retardant glass fiber cloth to fill the gap where the convex flange 11 and the concave flange 21 contact each other. The flame-retardant glass fiber cloth has an oxygen index of ≥35% and has high temperature resistance and flame retardant properties. When filling, the glass fiber cloth must be tightly stuffed into the gap to ensure that there is no omission to prevent the welding rod liquid from leaking through the gap during subsequent welding, thereby damaging the inner wall of the pipeline and affecting the normal use and service life of the pipeline.

[0039] Adjust the welding machine current to a preset value. This setting value is based on parameters such as the pipe material, wall thickness, and flange specifications. Use a small current multiple welding process. The single welding current is controlled at 80-120A. The welding length each time does not exceed 20mm. Adjacent welds need to be spaced 5-10mm apart to reduce the heat-affected zone, welding deformation, and stress concentration.

[0040] According to the above working method, the welding work of the welded liner flange can be completed.

[0041] In summary, the present welded liner flange with a special fixture and the installation method can solve the problems of axial creep, loosening and falling off of the lined pipe, thereby increasing the overall service life of the pipe. In addition, the sealing performance of the pipe can also be improved.

[0042] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A welded liner flange with a special fixture, characterized in that: include: A male and female flange joint (1) comprises a male flange (11), a male flange clamping boss (12) provided on the outside of the male flange (11), a male flange lining pipe (13) which is in close contact with the inner wall of the male flange (11) and has a folded end, and a male flange boss (15) provided on the lower middle portion of the inner side of the male flange (11) and protruding outwards; the vertical side surface of the male flange boss (15) is a male flange end sealing line end surface (16); A female socket flange joint (2) for embedding and connecting a male socket flange joint, comprising a female flange plate (21), a female flange clamping boss (22) provided on the outside of the female flange plate (21), a female flange lining pipe (23) closely attached to the inner wall of the female flange plate (21) and with its end folded over, and a female flange groove (27) provided on the inner side of the female flange plate (21) and recessed inwardly; the vertical side surface of the female flange groove (27) is a female flange end sealing line end surface (25); And a plurality of special fixtures (3), which include a fixture mounting seat (32) with a groove structure, a static top plate (31) and a dynamic top plate (33) arranged at both ends of the outer side of the groove structure of the fixture mounting seat (32); the dynamic top plate (33) is connected to the groove structure through a telescopic device (34); the static top plate (31) and the dynamic top plate (33) respectively support the outer side surfaces of the convex flange (11) and the concave flange (21) at both ends of the welding liner flange.

2. A welding liner flange with a special fixture according to claim 1, characterized in that: A clamp handle (35) for holding is also provided at the bottom of the clamp mounting seat (32).

3. The welding liner flange with a special fixture according to claim 1, characterized in that: The telescopic device (34) adopts a horizontal jack.

4. A welding liner flange with a special fixture according to claim 1, characterized in that: The assembly formed by the convex flange boss (15) and the convex flange lining tube (13) is inserted into the inner 1 / 2 to 1 / 4 of the concave flange groove (27) to prevent the hot melt welding slag medium from entering the lining layer.

5. The welding liner flange with a special fixture according to claim 1, characterized in that: The upper inner end of the convex flange (11) is provided with a convex flange chamfer (14), the end face (16) of the convex flange end sealing line is provided with a plurality of convex flange end sealing line notches (17), and the end sealing line (18) is provided in the convex flange end sealing line notches (17), the upper inner end of the concave flange is provided with a concave flange chamfer (24), the end face (25) of the concave flange end sealing line is provided with a plurality of concave flange end sealing line notches (26), and the end sealing line (18) is provided in the concave flange end sealing line notches (26).

6. The welding liner flange with a special fixture according to claim 1, characterized in that: The static top plate (31) and the dynamic top plate (33) are both crescent-shaped, and their inner contours coincide with the outer contour arc of the flange boss.

7. A method for installing a welded liner flange with a special fixture, characterized in that: The method is implemented by applying a welding liner flange with a special fixture according to any one of claims 1 to 6, comprising: S100: Select a pipe with a male and female socket flange joint (1) and a female socket flange joint (2) as a connection object, align the axes of the flange joints of the pipes to be connected, and after completing the axis alignment, slowly insert the male and female socket flange joint (1) into the female socket flange joint (2). The insertion process must be kept at a constant speed to avoid damaging the flange sealing surface due to excessively fast insertion; S200: Adjust the distance between the static top plate (31) and the dynamic top plate (33) by using the telescopic device (34), and then press the special fixture (3) against the outer sides of the convex flange (11) and the concave flange (21); S300: Adjust the telescopic device (34) again, and use the telescopic device (34) to lift the support seat to drive the movable top plate (33) installed on it to move forward. The surface of the lifting support seat is specially treated, and the roughness Ra≤0.8μm to ensure good contact with the movable top plate (33). During the movement, ensure that each contact point is uniformly stressed during clamping, and ensure that the internal connection is tight. After the convex flange (11) and the concave flange (21) are clamped on one side, use at least another set of special clamps (3) and follow the same operating procedures as above to clamp other parts of the flange to ensure that all four sides of the flange are evenly clamped to form a stable pre-tightened state. S400: Use flame-retardant glass fiber cloth to fill the gap between the convex flange (11) and the concave flange (21). The flame-retardant glass fiber cloth has an oxygen index of ≥35% and has high temperature resistance and flame retardant properties. When filling, the glass fiber cloth must be tightly stuffed into the gap to ensure that there is no leakage to prevent the welding rod liquid from leaking through the gap during subsequent welding, thereby damaging the inner wall of the pipeline and affecting the normal use and service life of the pipeline; S500: Adjust the welding machine current to a preset value. This setting value is based on parameters such as the pipe material, wall thickness, and flange specifications. Use a low-current, multiple-welding process. The single welding current is controlled at 80-120A. The welding length each time does not exceed 20mm. Adjacent welds must be spaced 5-10mm apart to reduce the heat-affected zone, welding deformation, and stress concentration.

8. A method for installing a welded liner flange with a special fixture according to claim 7, characterized in that: A plurality of the special fixtures (3) are used in combination. When facing a flange of smaller size, a group of special fixtures (3) is placed at both ends of the flange in the diameter direction, that is, the angle between the two groups of fixtures is 180°. For a flange of larger size, three or more groups of special fixtures (3) are used to ensure that each contact point is subjected to uniform force when the convex flange (11) and the concave flange (21) are clamped.

9. A method for installing a welded liner flange with a special fixture according to claim 8, characterized in that: A cooling measure needs to be taken around the welding portion, and the cooling measure is to cover the non-welding contact area between the convex flange (11) and the concave flange (21) with a wet rag.

Images