Pipeline connecting pipe fitting

Abstract

The utility model relates to the technical field of pipeline connecting structures, in particular to a pipeline connecting pipe fitting which comprises a first straight pipe section body, a bearing section body and at least one second straight pipe section body which are integrally cast, and the bearing section body is provided with a turning part which is bent or inclined from the axial direction of the pipe fitting to the radial direction. A corrosion buffer piece extending in the direction away from the bearing section body is integrally arranged in the middle of the outer wall of the turning part, a fixing through hole is formed in the corrosion buffer piece, and the fixing through hole is formed in the end, away from the bearing section body, of the corrosion buffer piece, so that a corrosion buffer area is formed between the fixing through hole and the outer wall of the turning part; the inner walls and the outer walls of the first straight pipe section body, the bearing section body and the second straight pipe section body are all covered with corrosion-resistant layers. The connecting pipe fitting has the beneficial effects that the corrosion buffer sheet is arranged outside the connecting pipe fitting, so that even if an easily-corroded point of the connecting pipe fitting is corroded in a long-term use process, generated corrosion products cannot fall off and be mixed into a conveyed water body, and water pollution is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to pipeline connecting structure technical field, especially pipeline connecting pipe fitting. BACKGROUND

[0002] Cast iron pipe fittings are widely used in municipal water supply, drainage, gas transmission and other fields. In order to improve its service life and aesthetic, usually need to be sprayed on the inner and outer surface of cast iron pipe fittings, to form a protective coating. Spraying process can effectively isolate the pipe fittings and the direct contact with the external environment, prevent the corrosion of corrosive medium, thereby prolonging the service life of pipe fittings.

[0003] However, in the spraying process, cast iron pipe fittings usually need to be fixed through the suspension device, in order to facilitate the spraying operation. The contact part of the suspension device and the pipe fitting often causes the coating to be unable to completely cover, forming a local non-sprayed area. These non-sprayed areas are exposed to the external environment, easy to be eroded by corrosive medium, forming process corrosion point. With the passage of time, these corrosion points will gradually expand, affect the overall performance and durability of the pipe fitting. Therefore, how to effectively reduce or eliminate the process corrosion point at the contact point of the suspension device and the pipe fitting without affecting the spraying efficiency has become a problem to be solved in the current technical field. SUMMARY

[0004] Therefore, in view of the above problems, the utility model provides a pipeline connecting pipe fitting.

[0005] The utility model is realized through the following technical schemes.

[0006] A pipeline connecting pipe fitting, comprising a first straight pipe segment body, a receiving segment body and at least one second straight pipe segment body integrally cast, the first straight pipe segment body, the receiving segment body and the second straight pipe segment body are communicated with each other to form a fluid flow channel capable of guiding fluid to flow from the inside of the first straight pipe segment body to the outside through the second straight pipe segment body and changing the flow direction of the fluid, the outer wall of the opening end of the first straight pipe segment body and the second straight pipe segment body is provided with a connecting structure, the receiving segment body is provided with at least one turning part bent or inclined from the axial direction to the radial direction, the outer wall of the turning part is integrally provided with a corrosion buffer piece extending away from the receiving segment body, a fixing through hole is formed in the corrosion buffer piece away from the receiving segment body, so that a corrosion buffer zone is formed between the fixing through hole and the outer wall of the turning part, and the inner wall and the outer wall of the first straight pipe segment body, the receiving segment body and the second straight pipe segment body are covered with a corrosion-resistant layer.

[0007] As a further improvement of the utility model, the corrosion-resistant layer forms a sealed cavity with only one opening, the first straight pipe segment body, the receiving segment body and the second straight pipe segment body are in the sealed cavity, and the shape and position of the opening of the sealed cavity correspond to the shape and position of the contact surface of the corrosion buffer sheet and the outer wall of the turning part.

[0008] As a further improvement of the utility model, the corrosion-resistant layer forms a sealed cavity with only one opening, the first straight pipe segment body, the receiving segment body and the second straight pipe segment body are in the sealed cavity, and the shape and position of the opening of the sealed cavity correspond to the shape and position of the contact surface of the corrosion buffer sheet and the outer wall of the turning part.

[0009] As a further improvement of the utility model, the corrosion buffer sheet comprises a connecting sheet integrally connected with the outer wall of the turning part and a positioning sheet integrally connected with the connecting sheet, the connecting sheet and the positioning sheet both have notches, the notches of the two form the fixed through hole, and the inner side contact point of the fixed through hole is located on the notch of the positioning sheet.

[0010] As a further improvement of the utility model, the contact surface of the connecting sheet and the outer wall of the turning part is in a strip shape, and the strip extends along the axial direction of the turning part.

[0011] As a further improvement of the utility model, the inner side contact point of the fixed through hole is located on the side of the notch of the positioning sheet away from the receiving segment body.

[0012] As a further improvement of the utility model, the inner side contact point of the fixed through hole is provided with a supplementary corrosion-resistant layer.

[0013] As a further improvement of the utility model, the corrosion-resistant layer and the supplementary corrosion-resistant layer are both epoxy plastic corrosion-resistant layers.

[0014] As a further improvement of the utility model, the first straight pipe segment body, the receiving segment body and at least one second straight pipe segment body are all made of nodular cast iron.

[0015] As a further improvement of the utility model, a clearance is arranged between the corrosion buffer sheet and the connecting structure.

[0016] The utility model has the advantages of:

[0017] 1. The corrosion buffer sheet in the application is arranged outside the connecting pipe fitting, so that even if the corrosion-prone point of the connecting pipe fitting is corroded in the long-term use process, the rust product (such as rust) generated thereby will not fall off and mix into the water body to be transported, so as to avoid causing water pollution.

[0018] 2. When spraying the connecting pipe fittings, the hook can be passed through the fixed through hole before spraying. At this time, there is no direct contact point between the suspension device (hook) and the body of the connecting pipe fitting (the first straight pipe section body, the receiving section body, and the second straight pipe section body), which effectively reduces the contact points between the suspension device and the connecting pipe fitting, thereby reducing the corrosion points of the connecting pipe fittings in this application. Moreover, since the connecting pipe fittings are installed by hooking them, the operation is simple and the phenomenon of the connecting pipe fittings falling off due to not being in a horizontal state can be avoided.

[0019] 3. During transportation, the connecting pipes can be controlled by passing the rope through the fixed through hole, and multiple connecting pipes can be transported in a string, reducing the loading and unloading time of individual pipes and improving transportation efficiency. Furthermore, since the connecting pipes are transported in a string through the fixed through hole, rolling, collision or detachment of the connecting pipes can be avoided during transportation, thereby preventing the corrosion-resistant layer from being worn.

[0020] 4. During the installation of connecting pipe fittings, the fasteners can be controlled to pass through the fixing through holes to fix the connecting pipe fittings on the installation device. Then, other pipe fittings can be controlled to connect to the connecting pipe fittings in this embodiment. That is, the connecting pipe fittings are used as a reference to install other pipe fittings. This can ensure that the connection position of other pipe fittings is accurate, reduce connection errors, and make the installation of other pipe fittings more orderly, thereby improving installation efficiency.

[0021] 5. When the suspension device (hook), rope and fastener pass through the fixed through hole, since the fixed through hole is opened on the side of the corrosion buffer plate away from the receiving section body, that is, there is a certain distance between the fixed through hole and the outer wall of the turning part, the suspension device (hook), rope and fastener can be prevented from touching the corrosion-resistant layer to a certain extent, thereby preventing the corrosion-resistant layer from being worn.

[0022] 6. Even if corrosion occurs, the corrosion buffer sheet should be corroded first, followed by the body of the connecting pipe fitting. This can delay the corrosion time of the connecting pipe fitting to a certain extent. Attached Figure Description

[0023] The preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings to help understand the purpose and advantages of this utility model, wherein:

[0024] Figure 1 This is a schematic diagram of the hook structure in the background art of a utility model patent;

[0025] Figure 2 This is a schematic diagram of the hanging pipe structure in the background art of a utility model patent;

[0026] Figure 3 This is a schematic diagram of the structure of the connecting pipe in an embodiment of the utility model patent when it is in the shape of a straight pipe;

[0027] Figure 4 Structure schematic view of the connecting pipe fitting in the utility model patent in the embodiment is in the shape of an elbow pipe;

[0028] Figure 5 Structure schematic view of the connecting pipe fitting in the utility model patent in the embodiment is in the shape of a tee pipe;

[0029] Figure 6 Structure schematic view of the connecting pipe fitting in the utility model patent in the embodiment is in the shape of an elbow pipe and is hooked by a hook;

[0030] Figure 7 Structure schematic view of the connecting pipe fitting in the utility model patent in the embodiment is in the shape of an elbow pipe and is hooked by a hook; Figure 6 Local enlarged view of A in the embodiment in the utility model patent;

[0031] Figure 8 Structure schematic view of the corrosion buffer sheet in the utility model patent.

[0032] Reference signs in the drawing: first straight pipe segment body 1, receiving segment body 2, second straight pipe segment body 3, connecting structure 4, turning portion 5, corrosion buffer sheet 6, fixing through hole 7, inner side contact point 8, connecting sheet 601, positioning sheet 602, hanging device 10, end portion 11, contact point 12. DETAILED DESCRIPTION

[0033] The utility model will be further described in detail below according to the drawing and the embodiment.

[0034] In the present specification, the orientation terms such as up, down, left, right, front, back, front face, back face, top, bottom and the like mentioned or possibly mentioned are defined with respect to the structure shown in the drawing, and the words "inner" and "outer" respectively refer to the direction towards or away from the geometric center of a particular component, which are relative concepts, so it is possible to change accordingly according to different positions and different use states. Therefore, these or other orientation terms should not be interpreted as restrictive terms.

[0035] Reference Figures 1 to 8 The utility model embodiment disclosed is:

[0036] A pipe connecting pipe fitting, comprising a first straight pipe segment body 1, a receiving segment body 2 and at least one second straight pipe segment body 3 integrally cast, the first straight pipe segment body 1, the receiving segment body 2 and the at least one second straight pipe segment body 3 are all made of nodular cast iron, the cost of making of nodular cast iron material is low, and compared with traditional cast iron, the weight is lighter, and excellent corrosion resistance is possessed.

[0037] The first straight pipe segment body 1, the receiving segment body 2 and the second straight pipe segment body 3 are communicated with each other to form a fluid flow channel capable of guiding fluid to flow from the inside of the first straight pipe segment body 1 to the outside through the second straight pipe segment body 3 and changing the flow direction of the fluid, and the opening end of the first straight pipe segment body 1 and the opening end of the second straight pipe segment body 3 are provided with a connecting structure 4, as shown in Figure 3 、 Figure 4 、 Figure 5 The second straight pipe segment body 3 can be one, two or three, that is, a two-way, three-way or four-way pipe fitting, as shown in Figure 1 、 Figure 2 In the spraying process, the hanging device 10 is in the shape of a hook, the end 11 penetrates into the connecting pipe fitting, and the end has only two contact points 12 in contact with the connecting pipe fitting, thereby effectively reducing the number of contact points.

[0038] However, in the spraying process, before spraying, the connecting pipe fitting needs to be hung on the hook, and then the pipe fitting needs to be adjusted so that the pipe fitting can be in a horizontal state to avoid falling off. After spraying, the pipe fitting needs to be adjusted, and the two contact points also need to be sprayed again. The contact points and the rest of the inner wall of the connecting pipe fitting are sprayed in multiple times, and it is difficult to ensure the uniformity of the coating around the contact points during spraying, resulting in a thinner or missing coating in the local area, which makes the contact points around the contact points easy to become the starting point of corrosion. Corrosion medium penetrates through these weak points and gradually expands to other parts of the pipe fitting, affecting the integrity of the overall structure. The corrosion products (such as rust) produced by the internal corrosion of the pipe fitting will fall off and mix into the transported water, causing water pollution and affecting water safety. Especially for pipe fittings used for drinking water transportation, internal corrosion will directly threaten public health. Therefore, in the present embodiment, the receiving segment body 2 is provided with at least one turning portion 5 curved or inclined from the axial direction of the pipe fitting to the radial direction, and the outer wall center of the turning portion 5 is integrally provided with a corrosion buffer piece 6 in the direction away from the receiving segment body 2.

[0039] Specifically, for example, as shown in Figure 3 The pipe fitting is in the shape of a straight pipe, and the turning portion 5 is inclined at an angle (15°-30°) from the axial direction of the pipe fitting to the radial direction, that is, the receiving segment body 2 is in the shape of a horn-shaped pipe body with a large lower part and a small upper part, and the corrosion buffer piece 6 is arranged on the turning portion 5. For example, Figure 4In the shown connecting pipe, the turning part 5 is bent from axial to radial, specifically, the connecting pipe is in the shape of a bent pipe (the receiving segment body 2 is a bent pipe segment body), at this time, the receiving segment body 2 is integrally composed of an inner semi-cylindrical pipe and an outer semi-cylindrical pipe which are both bent in the axial direction of the pipe, the length of the inner semi-cylindrical pipe in the axial direction of the pipe is less than the length of the outer semi-cylindrical pipe, the turning part 5 is the part of the inner semi-cylindrical pipe, and the corrosion buffer sheet 6 is arranged on the outer wall of the inner semi-cylindrical pipe; further as shown Figure 5 As shown, the connecting pipe is in the shape of a T-shaped three-way pipe, that is, two second straight pipe segment bodies 3 are arranged, and the first straight pipe segment body 1 and the receiving segment body 2 are arranged between the two straight pipe segment bodies, correspondingly, two turning parts 5 which are bent from axial to radial of the receiving segment body 2 are arranged at the connecting pipe, and the corrosion buffer sheet 6 is arranged on one of the turning parts 5; similarly to the three-way pipe, the connecting pipe can also be arranged in the shape of a four-way pipe, that is, three second straight pipe segment bodies 3 are arranged, and the turning part 5 is arranged above the turning part 5 of the receiving segment body 2.

[0040] Based on the structure, the fixing through hole 7 is arranged on the corrosion buffer piece 6, the fixing through hole 7 is arranged on the side of the corrosion buffer piece 6 away from the receiving section body 2, so that the corrosion buffer zone 9 is formed between the fixing through hole 7 and the outer wall of the turning part 5, and the inner wall and the outer wall of the first straight pipe section body 1, the receiving section body 2 and the second straight pipe section body 3 are covered with a corrosion-resistant layer (epoxy plastic corrosion-resistant layer). In this embodiment, the contact point of the suspension device and the connecting pipe is arranged outside the connecting pipe, so that even if the corrosion-prone point of the connecting pipe is corroded during long-term use, the corrosion products (such as rust) generated will not fall off and mix into the water being transported, thereby avoiding water pollution. In addition, when spraying, the hook can pass through the fixing through hole 7, and at this time, the suspension device (hook) and the body of the connecting pipe (first straight pipe section body 1, receiving section body 2 and second straight pipe section body 3) have no direct contact point, which further effectively reduces the direct contact point of the suspension device and the connecting pipe, thereby reducing the corrosion-prone point of the connecting pipe in this application. In addition, the connecting pipe can be controlled to pass through the fixing through hole 7 during transportation, and a plurality of connecting pipes can be transported in a string, thereby reducing the loading and unloading time of a single pipe and improving the transportation efficiency. In addition, the connecting pipe can be transported in a string through the fixing through hole 7, which can avoid rolling, collision or falling of the connecting pipe during transportation, thereby preventing the corrosion-resistant layer from being worn. At the same time, during the installation of the connecting pipe, the fastener can be controlled to pass through the fixing through hole 7 first, and the connecting pipe is fixed to the installation device, and then other pipes are connected to the connecting pipe of this embodiment, that is, the connecting pipe is taken as a reference, and other pipes are installed, which can ensure the accurate connection position of other pipes, reduce the connection error, and make the installation of other pipes more orderly, thereby improving the installation efficiency. At the same time, when the suspension device (hook), the rope and the fastener pass through the fixing through hole 7 respectively, since the fixing through hole 7 is arranged on the side of the corrosion buffer piece 6 away from the receiving section body 2, and the corrosion buffer zone 9 is formed between the fixing through hole 7 and the outer wall of the turning part 5, when the suspension device (hook), the rope and the fastener pass through the fixing through hole 7, there is still a certain distance (1-3 cm) from the outer wall of the turning part 5, so that the suspension device (hook), the rope and the fastener can not touch the corrosion-resistant layer, thereby preventing the corrosion-resistant layer from being worn.

[0041] It is worth mentioning that the connecting pipe is in a horizontal state Figure 4When the elbow-shaped connecting pipe is installed, the first straight pipe body 1 and the second straight pipe body 3 of the connecting pipe are inclined upward under the effect of gravity after the connecting pipe is penetrated by the fastener, which further facilitates the installation of other hangers. The corrosion buffer 6 is arranged on the inner half-cylinder pipe and extends away from the elbow pipe body in an integrated manner, which can avoid the corrosion buffer 6 from being touched by workers during installation to a certain extent, compared with the case where the corrosion buffer 6 is directly arranged on the side walls of the elbow pipe body.

[0042] In addition, in the present embodiment, even if corrosion occurs during long-term use, the corrosion buffer 6 is corroded first, and then the body of the connecting pipe is corroded, which can delay the corrosion time of the connecting pipe to a certain extent. Based on the above, the corrosion-resistant layer forms a sealed cavity with only one opening, and the first straight pipe body 1, the receiving pipe body 2, and the second straight pipe body 3 are located in the sealed cavity. The shape and position of the opening of the sealed cavity correspond to the shape and position of the contact surface between the corrosion buffer 6 and the outer wall of the turning part 5, that is, the corrosion buffer 6 is not wrapped by the corrosion-resistant layer. During long-term use of the connecting pipe, the corrosion buffer 6 is usually the starting point of corrosion, and the corrosion site can only extend from the opening of the sealed cavity to the first straight pipe body 1, the receiving pipe body 2, and the second straight pipe body 3, that is, the first straight pipe body 1, the receiving pipe body 2, and at least one second straight pipe body 3 have a certain buffer time before being corroded. In the present embodiment, the corrosion buffer 6 (especially the corrosion buffer 9) can be made of pure metal or alloy that is more resistant to environmental corrosion than ductile cast iron, such as aluminum alloy, and is connected to the turning part 5 by welding to further slow down the corrosion rate. Alternatively, the corrosion buffer 6 is also made of ductile cast iron material and is integrally formed with the receiving pipe body 2 during production. In specific cases, the corrosion buffer 6 in the present embodiment can also be connected to an external power source to apply a cathode current to the corrosion buffer 6 (to achieve an electric corrosion prevention effect), thereby reducing the corrosion rate of the corrosion buffer 6 and further slowing down the corrosion rate of the connecting pipe as a whole.

[0043] As a further improvement, the corrosion buffer piece 6 is formed in a sealed cavity with only one opening, the first straight pipe segment body 1, the receiving segment body 2, the second straight pipe segment body 3 and the corrosion buffer piece 6 are all in the sealed cavity, the fixed through hole 7 has an inner side contact point 8, the shape and position of the opening of the sealed cavity correspond to the shape and position of the inner side contact point 8 of the fixed through hole 7; that is, the corrosion buffer piece 6 in this embodiment is also made of nodular cast iron material and can be integrally formed with the receiving segment body 2 during production. In the spraying process, the contact point of the suspension device with the fixed through hole 7 is the inner side contact point 8 in this embodiment. Correspondingly, during long-term use, the inner side contact point 8 is usually the starting point of corrosion. The corrosion point first spreads at the inner wall of the fixed through hole 7. Due to the formation of the corrosion buffer zone 9 between the fixed through hole 7 and the outer wall of the turning part 5, the corrosion point first spreads at the inner wall of the fixed through hole 7, then corrodes and spreads along the corrosion buffer zone 9, and finally spreads and extends in the direction of the receiving segment body 2 and the first straight pipe segment body 1 (or the second straight pipe segment body). The corrosion time of the corrosion buffer piece 6 is prolonged, the corrosion time of the main body of the connecting pipe fitting is indirectly delayed, and the service life of the connecting pipe fitting is improved.

[0044] Based on the above (when the connecting pipe fitting is in a bent pipe shape), Figure 4 As shown in the drawings, the corrosion buffer piece 6 includes a connecting piece 601 integrally connected with the outer wall of the turning part 5 and a positioning piece 602 integrally connected with the connecting piece 601. The connecting piece 601 and the positioning piece 602 both have notches, and the notches of the two form the fixed through hole 7. The inner side contact point 8 of the fixed through hole 7 is located on the notch of the positioning piece 602. The inner side contact point 8 of the fixed through hole 7 is located on the side of the notch of the positioning piece 602 away from the receiving segment body 2. That is, the position of the inner side contact point 8 of the fixed through hole 7 is located on the side of the fixed through hole 7 farther away from the outer wall of the turning part 5. In this way, the distance between the corrosion point and the outer wall of the turning part 5 is prolonged, and the corrosion time of the corrosion buffer piece 6 corroding the outer wall of the turning part 5 is also prolonged, so as to improve the service life of the connecting pipe fitting.

[0045] In this embodiment, the contact surface of the connecting piece 601 and the outer wall of the turning part 5 is in a long strip shape, and the long strip extends along the axial direction of the turning part 5.

[0046] An avoiding interval is arranged between the corrosion buffer piece 6 and the connecting structure 4, so as to avoid the end of another pipe fitting colliding with or rubbing against the surface of the corrosion buffer piece 6 when the connecting structure 4 is connected with another pipe fitting.

[0047] In addition, in another embodiment, due to the inner contact point 8, the shape and position of the opening of the sealing cavity correspond to the shape and position of the inner contact point 8 of the fixed through hole 7, the inner contact point 8 of the fixed through hole 7 is provided with a supplementary corrosion-resistant layer (epoxy plastic corrosion-resistant layer); after the spraying is completed, the spraying device is controlled to spray at the inner contact point 8. Although the coating uniformity around the inner contact point 8 is difficult to guarantee through the second spraying, compared with no coating on the inner contact point 8, the supplementary corrosion-resistant layer can further prolong the corrosion time of the outer wall of the transition part 5 corroded by the corrosion buffer piece 6.

[0048] The connection pipe spraying process:

[0049] a, surface treatment: take the pipe blank, the pipe blank includes a first straight pipe body 1, a receiving segment body 2, at least one second straight pipe body 3, the receiving segment body 2 is formed by welding or integrally casted with a corrosion buffer piece 6, the pipe blank is surface treated to remove oil stains, oxidation layer, stains and the like;

[0050] b, preheating: transport the pipe blank to the heating furnace and preheat at 145-155°C for 35 minutes;

[0051] c, suspension spraying: take out the pipe blank, control the hooking part of the hanging device (hook) to pass through the fixed through hole 7 of the corrosion buffer piece 6, so that the pipe blank is hung on the hanging device, when the pipe blank is in a static state under the action of gravity, the outer surface and inner wall of the pipe blank are sprayed with epoxy plastic powder by the electrostatic spraying equipment;

[0052] d, solidification: take out the pipe blank, transport the pipe blank to the solidification furnace, and solidify at 210-230°C for 40 minutes, at this time, the epoxy plastic powder is solidified into a corrosion-resistant layer, that is, the connection pipe of the embodiment is obtained.

[0053] In another embodiment, in step c, after the outer surface and inner wall of the pipe blank are sprayed with epoxy plastic powder by the electrostatic spraying equipment, step c1 is further provided, the pipe blank is taken out, the contact point (inner contact point 8) of the hanging device and the fixed through hole 7 is supplemented by the electrostatic spraying equipment, at this time, in step d, the epoxy plastic powder at this position is solidified into a supplementary corrosion-resistant layer.

[0054] Finally, it should be noted that: the above implementation cases are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing implementation cases, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing implementation cases, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the implementation cases of the present application.

Claims

1. A pipe connecting fitting, comprising a first straight pipe section body (1), a receiving section body (2) and at least one second straight pipe section body (3) integrally cast, the first straight pipe section body (1), the receiving section body (2) and the second straight pipe section body (3) being in communication with each other to form a fluid flow channel capable of guiding fluid to flow from inside the first straight pipe section body (1) to flow out through the second straight pipe section body (3) and changing the direction of fluid flow, and a connecting structure (4) being provided on the outer wall of the open end of the first straight pipe section body (1) and the second straight pipe section body (3), characterized in that: The receiving section body (2) is provided with at least one bending or tilting transition (5) from axial to radial, the outer wall of the transition (5) is integrally provided with a corrosion buffer sheet (6) extending away from the receiving section body (2), the corrosion buffer sheet (6) is provided with a fixed through hole (7), the fixed through hole (7) is provided on the side of the corrosion buffer sheet (6) away from the receiving section body (2), so that the fixed through hole (7) and the outer wall of the transition (5) form a corrosion buffer zone (9), the inner wall and the outer wall of the first straight pipe section body (1), the receiving section body (2) and the second straight pipe section body (3) are covered with a corrosion-resistant layer.

2. A pipe coupling according to claim 1, wherein: The corrosion-resistant layer forms a sealed cavity with only one opening, the first straight pipe section body (1), the receiving section body (2) and the second straight pipe section body (3) are in the sealed cavity, and the shape and position of the opening of the sealed cavity correspond to the shape and position of the contact surface of the corrosion buffer sheet (6) and the outer wall of the transition (5).

3. A pipe coupling according to claim 1, wherein: The corrosion-resistant layer forms a sealed cavity with only one opening, the first straight pipe section body (1), the receiving section body (2) and the second straight pipe section body (3) are in the sealed cavity, and the shape and position of the opening of the sealed cavity correspond to the shape and position of the contact surface of the corrosion buffer sheet (6) and the outer wall of the transition (5).

4. A pipe coupling according to claim 3, wherein: The corrosion buffer sheet (6) includes a connecting sheet (601) integrally connected with the outer wall of the transition (5) and a positioning sheet (602) integrally connected with the connecting sheet (601), the connecting sheet (601) and the positioning sheet (602) both have notches, and the notches of the two form the fixed through hole (7), and the inner side contact point (8) of the fixed through hole (7) is located on the notch of the positioning sheet (602).

5. A pipe coupling according to claim 4, wherein: The contact surface of the connecting sheet (601) and the outer wall of the transition (5) is in the shape of a long strip, and the long strip extends along the axial direction of the transition (5).

6. A pipe coupling according to claim 4, wherein: The inner side contact point (8) of the fixed through hole (7) is located on the side of the notch of the positioning sheet (602) away from the receiving section body (2).

7. A pipe coupling according to claim 6, wherein: The inner side contact point (8) of the fixed through hole (7) is provided with a supplementary corrosion-resistant layer.

8. A pipe coupling according to claim 7, wherein: The corrosion-resistant layer and the supplementary corrosion-resistant layer are both epoxy plastic corrosion-resistant layers.

9. A pipe coupling according to claim 1, wherein: The first straight pipe section body (1), the receiving section body (2) and at least one second straight pipe section body (3) are all made of nodular cast iron.

10. A pipe coupling according to claim 1, wherein: An avoidance interval is provided between the corrosion buffer sheet (6) and the connecting structure (4).

Images