A pipe plugging assembly and a pipe plugging welding method

Abstract

The application provides a pipeline plugging assembly and a pipeline plugging and welding method. The pipeline plugging assembly comprises a fixed plugging part and a sealing plug in a pipeline to be welded. The fixed plugging part and the sealing plug are respectively sealed and filled on opposite sides of a welding position, or the fixed plugging part is sealed and filled on one side of the welding position. The fixed plugging part is a block structure or a sheet structure made of a surfactant. The sealing plug is provided with a through hole for a protective gas pipe to pass through. The protective gas pipe is used for filling protective gas into a sealed area where the welding position is located. The sealing plug can move in the pipeline to be welded under the pulling of the protective gas pipe. The fixed plugging part does not produce carbide, and solves the hidden danger of pipeline plugging. The sealed area where the welding position is located has good sealing performance, and can fully protect the root weld. Part of grease in the pipeline can be removed, an alkaline environment is formed in the pipeline to protect the boiler, and the welding efficiency of the pipeline is improved.

Description

Technical Field

[0001] This invention relates to the field of pipeline welding technology, and in particular to a pipeline plugging component and a pipeline plugging welding method. Background Technology

[0002] In existing technologies, some pipe materials require argon purging to prevent root weld oxidation during welding. This is necessary before welding. High-alloy steel pipes, which, according to specifications, refer to heat-resistant steel with a chromium content greater than 3% or a total alloy content greater than 5%, generally include 9%Cr-12%Cr martensitic heat-resistant steel, austenitic stainless steel, and nickel-based alloys.

[0003] Existing methods for sealing the welding area of ​​small-diameter pipes include: using paper cutters or water-soluble paper rolled into balls and stuffing them into the pipe; or using water-soluble paper rolled into a cone shape and stuffing it into the pipe; or using water-soluble adhesive to stick water-soluble paper into the pipe.

[0004] The applicant has discovered that the prior art has at least the following technical problems:

[0005] On the one hand, the existing pipe sealing methods are prone to clogging. The reasons are as follows: (1) Although knife paper or water-soluble paper is more soluble in water than other materials, if knife paper or water-soluble paper is too close to the welding area, it will not burn due to the heat of the welding area and the inert protective gas, but will form carbides; (2) The pipes that need to be protected by protective gas in the boiler area are concentrated on the boiler heating surface. Due to the improvement of various parameters such as boiler thermal efficiency, most boiler heating surfaces are designed as serpentine or π-shaped pipes, which are prone to siltation; and the number of pipes is increased, and the pipe diameter is reduced. (3) The medium in the heating surface pipe is high temperature and high pressure steam, which has little effect on the corrosion of the formed carbides and cannot burn such carbides, and will also cause the carbides to form. (4) Water-soluble paper will form lumpy hard objects when it is dry-burned at high temperature without being dissolved in water. The formed substance is not easily soluble in water. In particular, when a large amount of water-soluble paper is gathered in a certain place or in a clump, the above phenomenon will be more serious.

[0006] The above reasons can easily lead to the accumulation of carbon deposits inside the pipes, which cannot be completely blown out by boiler water pressure, flushing, and blow-out. In addition, the steam generated during blow-out or operation can also blow the carbon deposits together, eventually causing pipe blockage. If the pipe is blocked for a long time, it will overheat. Prolonged high temperature will cause the pipe to burst, leading to unit "unscheduled shutdown" and affecting unit reliability.

[0007] On the other hand, the existing pipe sealing methods do not provide good protection for welds. The reasons are: (1) Compared with the other two sealing methods, paper ball sealing has more gaps with the inside of the pipe; (2) Water-soluble paper or knife paper is made of plant fibers and has large pores; (3) The carbides formed by knife paper or water-soluble paper when heated are relatively loose.

[0008] The above situations can lead to air leakage in the protective gas chamber, failing to provide adequate protection for the root weld and resulting in root weld oxidation. During long-term operation with high-temperature, high-pressure steam, this weld will suffer from blow-through damage, shortening its service life and increasing the risk of boiler tube rupture. Summary of the Invention

[0009] The purpose of this invention is to provide a pipe sealing component and a pipe sealing welding method to solve the technical problems of existing methods that use rolled-up paper or water-soluble paper to seal the area to be welded, which easily clogs the pipe and provides poor protection for the weld. The various technical effects of the preferred solutions provided by this invention are detailed below.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] The pipe plugging assembly provided by the present invention includes a fixed plugging part and a sealing plug located inside the pipe to be welded, wherein:

[0012] The fixing and sealing parts and the sealing plug are respectively sealed and filled on opposite sides of the position to be welded, or the fixing and sealing parts are sealed and filled on one side of the position to be welded;

[0013] The fixed sealing part is a block structure or sheet structure made of surfactant;

[0014] The sealing plug is provided with a through hole for the protective gas tube to pass through. The protective gas tube is used to fill the sealing area where the welding position is located with protective gas, and the sealing plug can move inside the pipe to be welded under the pull of the protective gas tube.

[0015] Preferably, the fixing and sealing part is a frustum-shaped structure, the upper bottom diameter of the fixing and sealing part is smaller than the inner diameter of the pipe to be welded, the lower bottom diameter of the fixing and sealing part is larger than the inner diameter of the pipe to be welded, and the lower bottom of the fixing and sealing part faces the position to be welded.

[0016] Preferably, the thickness of the fixing and sealing part is 5-10mm.

[0017] Preferably, the sealing plug is made of a polymer material.

[0018] Preferably, the protective gas pipe is an inert gas pipe, and the outlet of the inert gas pipe faces the position to be welded.

[0019] The present invention also provides a pipe plugging welding method, using the above-mentioned pipe plugging assembly, the plugging welding method comprising:

[0020] The fixing and sealing parts and the sealing plug are respectively sealed and filled on both sides of the position to be welded;

[0021] Pass the protective gas tube through the through hole and fill the sealed area where the welding position is located with protective gas;

[0022] After inflation, weld the first position to be welded.

[0023] Preferably, the sealing welding method further includes: before filling the sealing area where the welding position is located with protective gas, it further includes:

[0024] A polymer sealing strip is used to wrap and seal the area to be welded. The polymer sealing strip can melt during welding.

[0025] Preferably, the sealing welding method further includes:

[0026] After welding the first position to be welded, pull the protective gas tube so that the sealing plug moves inside the pipe to be welded under the pull of the protective gas tube until the sealing plug moves to one side of the second position to be welded.

[0027] Insert the new fixing and sealing part into the other side of the second welding position;

[0028] Use a new polymer sealing strip to wrap and seal the second position to be welded;

[0029] Fill the sealed area where the second welding position is located with protective gas;

[0030] Weld the second position to be welded.

[0031] Preferably, repeat the above operation until only one welding position remains in the entire pipe where a sealing plug cannot be used.

[0032] Preferably, when welding the last position to be welded on the pipeline, the fixing and sealing part is sealed and filled on the side of the last position to be welded, so that the last position to be welded is in a protective atmosphere.

[0033] The pipe plugging assembly and pipe plugging welding method provided by this invention have the following advantages compared with the prior art: the fixed plugging part made of surfactant will not produce carbides, thus solving the hidden danger of pipe blockage; the sealing area formed at the welding position has good sealing performance and can fully protect the root weld; it can remove some grease in the pipe and form an alkaline environment to protect the boiler inside the pipe; and the sealing plug, in conjunction with the protective gas pipe, can move inside the pipe to be welded, thereby realizing mobile protection for different welding positions and improving the welding efficiency of the pipe. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the mating structure between the pipe plugging component and the pipe to be welded;

[0036] Figure 2 This is a schematic diagram of the moving structure of the protective gas pipe inside the pipe to be welded.

[0037] In the diagram: 1. Fixed sealing part; 2. Sealing plug; 21. Through hole; 3. Protective gas tube; 4. Polymer sealing strip; 100. Pipe; 101. Weld. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0039] In the description of this invention, it should be understood that the terms "center," "length," "width," "height," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and "side," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0040] This invention provides a pipe plugging component and a pipe plugging welding method that do not generate carbides inside the pipe, have better sealing performance, can achieve mobile protection for different welding positions, and improve the welding efficiency of the pipe.

[0041] The following is combined with Figure 1 and Figure 2 The technical solution provided by this invention will be described in more detail below.

[0042] Example 1:

[0043] See Figure 1 and Figure 2 As shown, the present invention provides a pipe sealing assembly, including a fixed sealing part 1 and a sealing plug 2 located in the pipe 100 to be welded, wherein: the fixed sealing part 1 and the sealing plug 2 respectively seal and fill the opposite sides of the position to be welded, or the fixed sealing part 1 seals and fills one side of the position to be welded; the fixed sealing part 1 is a block structure or sheet structure made of surfactant; the sealing plug 2 is provided with a through hole 21 for a protective gas tube 3 to pass through, the protective gas tube 3 is used to fill the sealing area where the position to be welded is located with protective gas, and the sealing plug 2 can move within the pipe 100 to be welded under the pull of the protective gas tube 3, moving to the side of other positions to be welded.

[0044] Specifically, for the last weld 101 of the pipe 100, the fixed sealing part 1 is sealed and filled on one side of the position to be welded. For the remaining welds 101 of the pipe 100, the fixed sealing part 1 and the sealing plug 2 are respectively sealed and filled on the opposite sides of the position to be welded.

[0045] The pipe 100 to be welded includes multiple pipe segments with weld seams 101. It should be understood that the pipe segments are interconnected, and the sealing plug 2 can move within multiple pipe segments under the pull of the protective gas pipe 3. However, there are weld seams 101 between the pipe segments. The purpose of this embodiment is to use a welding device to weld the weld seams 101 between the pipe segments (i.e., the position to be welded is the weld seam 101).

[0046] In order to facilitate pulling the protective air tube 3, a protruding structure can be fixed on the protective air tube 3, so that the user can hold it or pull it with an external power device.

[0047] The pipe plugging assembly of this embodiment has the following beneficial effects: the fixed plugging part 1 made of surfactant does not produce carbon deposits compared with the knife paper or water-soluble paper in the prior art, thus solving the hidden danger of pipe 100 blockage.

[0048] In existing technologies, paper wads or water-soluble paper are inserted into the pipe 100 in the form of paper balls. Compared with the other two sealing methods, paper ball sealing leaves more gaps inside the pipe 100. Water-soluble paper or paper wads are made of plant fibers, which have large pores. The carbides formed by paper wads or water-soluble paper when heated are relatively loose. In this embodiment, the fixing and sealing part 1 made of surfactant is inserted into the pipe 100, leaving fewer gaps. The resulting sealing area at the welding position has good sealing performance and can fully protect the root weld 101.

[0049] On the other hand, the fixed sealing part 1 made of surfactant can remove some of the grease in the pipe 100 and form an alkaline environment within the pipe 100.

[0050] The sealing plug 2, in conjunction with the protective gas tube 3, can move within the pipe 100 to be welded, thereby achieving mobile protection for different welding positions and improving the welding efficiency of the pipe 100.

[0051] The following explanation uses weld 101 as the location to be welded.

[0052] As an alternative implementation, see [link to implementation details]. Figure 1 As shown, the fixed sealing part 1 has a frustum-shaped structure. The upper bottom diameter of the fixed sealing part 1 is smaller than (slightly smaller than) the inner diameter of the pipe 100 to be welded, and the lower bottom diameter of the fixed sealing part 1 is larger than (slightly larger than) the inner diameter of the pipe 100 to be welded. The lower bottom of the fixed sealing part 1 faces the position to be welded.

[0053] The frustum-shaped fixing and sealing part 1 is easy to insert into the pipe 100, and the bottom of the fixing and sealing part 1 faces the position to be welded (weld 101), such as... Figure 1 As shown, this facilitates the improvement of the sealing performance of weld 101.

[0054] As an optional implementation, specifically, in this embodiment, the fixed sealing part 1 has a sheet-like structure with a thickness of 5-10mm, which is convenient to be inserted into the pipe 100 to seal and protect the weld 101.

[0055] As an alternative implementation, see [link to implementation details]. Figure 1 As shown, the sealing plug 2 in this embodiment is made of polymer material.

[0056] The sealing plug 2 is made of elastic material and is squeezed into the pipe 100 to seal it. When the protective air pipe 3 passes through the through hole 21 of the sealing plug 2, it can seal one side of the weld 101.

[0057] See Figure 1As shown, one side of the weld 101 is sealed by the fixed sealing part 1, and the other side is sealed by the sealing plug 2 and the protective gas tube 3. The weld 101 is located between the fixed sealing part 1 and the sealing plug 2. When the weld 101 is inflated for protection, a polymer sealing strip 4 is used to wrap the weld 101. The polymer sealing strip 4 wraps the weld 101 360°. With this setting, the weld 101 can be in a sealed area to prevent the protective gas from leaking.

[0058] Specifically, the protective gas pipe 3 is an inert gas pipe, with the outlet of the inert gas pipe facing the position to be welded. The protective gas is an inert gas, such as argon or nitrogen, to prevent oxidation of the root weld.

[0059] Example 2:

[0060] See Figure 1 and Figure 2 As shown, this embodiment provides a pipe plugging welding method. Using the above-mentioned pipe plugging assembly, the plugging welding method includes: sealing and filling the fixed plugging part 1 and the sealing plug 2 on opposite sides of the position to be welded; passing the protective gas pipe 3 through the through hole 21 to fill the sealed area where the position to be welded is located with protective gas; after the gas filling is completed, welding is performed on the first position to be welded.

[0061] Figure 2 The arrows in the figure indicate the direction of movement of the protective gas pipe 3. The two welds 101 highlighted in the figure are the first weld 101 (left side of the figure) and the last weld 101 (right side of the figure) of the pipe 100.

[0062] The fixed sealing part 1 is a block or sheet structure made of surfactant, such as soap flakes. The main component of soap is sodium stearate. Using soap flakes can ensure the sealing of the gas chamber. In addition, soap flakes are soluble in water and have a certain degree of lubrication. Even if the soap flakes are not removed, after the boiler water pressure and flushing processes, it can still ensure that the pipe 100 is not blocked before the overall operation. In addition, it can remove excess grease in the pipe and ensure the alkaline environment inside the boiler.

[0063] As an optional implementation, the sealing welding method further includes: before filling the sealing area where the welding position is located with protective gas, it further includes: wrapping and sealing the welding position with a polymer sealing strip 4, wherein the polymer sealing strip 4 can melt during welding.

[0064] The polymer sealing strip 4 wraps around the weld 101 360°, thus ensuring that the weld 101 is in a sealed area and preventing leakage of the protective gas. Furthermore, the polymer sealing strip 4 melts during welding without affecting the welding process of the weld 101.

[0065] As an alternative implementation, see [link to implementation details]. Figure 1 and Figure 2 As shown, the sealing welding method further includes: after welding the first position to be welded, pulling the protective gas tube 3, causing the sealing plug 2 to move within the pipe 100 to be welded under the pull of the protective gas tube 3, until the sealing plug 2 moves to one side of the second position to be welded; inserting a new fixing sealing part 1 into the other side of the second position to be welded; wrapping and sealing the second position to be welded with a new polymer sealing strip 4; filling the sealed area where the second position to be welded is located with protective gas; and welding the second position to be welded. The above operations are repeated until only one position of the entire pipe 100 remains that cannot be welded using the sealing plug 2.

[0066] The above method, for each weld 101, involves inserting a fixed sealing part 1 into one side of the weld 101 between adjacent pipe sections. For example, for... Figure 2 For the first weld 101, the fixing and sealing part 1 and the sealing plug 2 are respectively inserted into the upper and lower sides of the first weld 101 (upper and lower sides only indicate their positions in the figure). Figure 2 Regarding the last weld 101 in the pipeline, the fixing and sealing part 1 is inserted into the upper side of the last weld 101 (the upper side is only shown in the figure). Except for the last weld 101 of the pipeline 100, the sealing plug 2 is filled on the other side of the weld 101, and the polymer sealing strip 4 is wrapped around the weld 101, so that the weld 101 is in the sealed area and welding is carried out under the protection of the protective gas.

[0067] Furthermore, by pulling the protective gas tube 3, the sealing plug 2 can be moved synchronously. The protective gas tube 3 can provide gas protection at different weld seam 101 positions without being pulled out, thereby improving the gas filling efficiency and thus improving the welding efficiency.

[0068] As an optional implementation, when welding the last position to be welded on the pipe 100, the fixing and sealing part 1 is sealed and filled on the side of the last position to be welded, so that the last position to be welded is in a protective atmosphere.

[0069] For the last weld 101 of the pipeline 100, since the front side of the weld 101 is already in the atmosphere of protective gas, and since the inside of the pipeline 100 is filled with protective gas at this time, the fixed sealing part 1 will be inserted into the pipeline 100 before the last weld joint is aligned. Therefore, it is only necessary to use a gas needle to fill the gas from the weld joint position to meet the protection requirements. The other side is sealed with the fixed sealing part 1, which greatly reduces the workload of filling the protective gas (argon and other inert gases).

[0070] The specific features, structures, or characteristics described in this specification may be combined in any suitable manner in one or more embodiments or examples.

[0071] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0072] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A pipe plugging assembly, characterized by, The pipe sealing assembly comprises a fixed sealing part and a sealing plug located in the pipe to be welded, wherein: The fixed sealing part and the sealing plug are respectively filled in the opposite sides of the position to be welded, or the fixed sealing part is filled in one side of the position to be welded. The fixed sealing part is a block structure or a sheet structure made of surfactant. The sealing plug is provided with a through hole for a protective gas pipe to pass through, the protective gas pipe is used to fill protective gas into the sealed area where the position to be welded is located, and the sealing plug can move in the pipe to be welded under the pulling of the protective gas pipe.

2. The pipe plugging assembly of claim 1, wherein, The fixed sealing part is a circular truncated cone structure, the upper base diameter of the fixed sealing part is smaller than the inner diameter of the pipe to be welded, the lower base diameter of the fixed sealing part is larger than the inner diameter of the pipe to be welded, and the lower base of the fixed sealing part faces the position to be welded.

3. The pipe plugging assembly of claim 1 or 2, wherein, The thickness of the fixed sealing part is 5-10mm.

4. The pipe plugging assembly of claim 1, wherein, The sealing plug is made of high polymer material.

5. The pipe plugging assembly of claim 1, wherein, The protective gas pipe is an inert gas pipe, and the gas outlet head of the inert gas pipe faces the position to be welded.

6. A method of pipe stop welding, characterized by, The pipe sealing assembly is used in the pipe sealing and welding method, which comprises the following steps: The fixed sealing part and the sealing plug are respectively filled in the opposite sides of the position to be welded. The protective gas pipe is passed through the through hole, and the protective gas is filled into the sealed area where the position to be welded is located. After the filling of the protective gas is completed, the first position to be welded is welded.

7. The method of pipe stop welding of claim 6, wherein, The pipe sealing and welding method further comprises the following steps before the protective gas is filled into the sealed area where the position to be welded is located: A high polymer sealing strip is used to wrap and seal the position to be welded, and the high polymer sealing strip can be melted during welding.

8. The method of pipe stop welding of claim 6, wherein, The pipe sealing and welding method further comprises the following steps: After the welding of the first position to be welded is completed, the protective gas pipe is pulled, so that the sealing plug moves in the pipe to be welded under the pulling of the protective gas pipe, until the sealing plug moves to one side of the second position to be welded. A new fixed sealing part is inserted into the other side of the second position to be welded. A new high polymer sealing strip is used to wrap and seal the second position to be welded. The protective gas is filled into the sealed area where the second position to be welded is located. The second position to be welded is welded.

9. The method of pipe stop welding of claim 8, wherein, The above operations are repeated until only the last position to be welded which cannot use the sealing plug is left in the whole pipe.

10. The method of pipe stop welding of claim 6, wherein, When the last position to be welded of the pipe is welded, the fixed sealing part is filled in the side of the last position to be welded, so that the last position to be welded is in a protective atmosphere.

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