Straight pipe with corrosion-resistant lining

Abstract

The utility model discloses a straight pipe adopting a corrosion-resistant lining, which comprises an outer pipe and an inner pipe made of a corrosion-resistant material, two ends of the outer pipe are provided with socket parts, the middle of the outer pipe is provided with a straight pipe part, the straight pipe part and the socket parts are coaxially connected, the inner pipe covers the inner wall of the outer pipe, the outer walls of the socket parts at the two ends of the outer pipe and the end surfaces of the socket parts, and the inner pipe comprises an inner sleeve and two socket sleeves. The outer pipe and the inner sleeve are cylindrical, the inner sleeve is sleeved with the outer pipe, and the two inserting opening sleeves cover the outer walls of the two inserting opening parts respectively. The inner pipe made of the corrosion-resistant material covers the inner wall of the outer pipe, the end faces of the spigot parts at the two ends and the outer walls of the spigot parts, when liquid is conveyed, the part, making contact with the pipe, of the liquid is completely wrapped by the corrosion-resistant material, a good corrosion-resistant effect is achieved, the two adjacent straight pipes are connected through the double-bearing pipe fitting made of the corrosion-resistant material, and when the two adjacent straight pipes are connected, the corrosion-resistant effect is good. The inner ring of the sealing ring tightly presses the spigot sleeve on the outer wall of the spigot part to prevent the inner pipe from falling off, and meanwhile layering caused by direct impact of water flow on the port of the straight pipe is prevented.

Description

Technical Field

[0001] The utility model belongs to the technical field of pipes, in particular to a straight pipe with a corrosion-resistant lining. Background Art

[0002] Pipes are widely used in liquid transportation pipe network systems. When used, the parts of the pipes that come into contact with the liquid are required to have good corrosion resistance to prevent the pipes from rusting due to long-term contact with the liquid, which affects the quality of the transported liquid. Currently, more composite pipes are used, generally with a metal pipe as the outer layer and a plastic pipe as the inner layer, and the inner and outer layers are compounded by a composite process. That is, the inner wall of the outer metal pipe is coated with a plastic pipe. The structure of the existing composite pipe is a socket structure, with one end of the metal pipe being a spigot end and the other end being a bell end. When the pipe network is installed, multiple composite pipes are connected in sequence, and the spigot end of a composite pipe is inserted into the bell end of the adjacent composite pipe. When the inner wall of the metal pipe is coated with anti-corrosion, the middle part and the spigot end of the metal pipe are coated with an inner plastic pipe, and the inner wall of the bell end and the outer wall of the spigot end are generally directly painted with anti-corrosion paint, or sprayed / coated. However, this method does not make the anti-corrosion coating of the pipe form a whole. During use, the long-term scouring of the liquid in the pipeline will cause the liquid to penetrate into the inner wall of the metal pipe through the gaps between different materials, resulting in failure of anti-corrosion and corrosion of the pipe wall, affecting the service life of the pipeline and polluting the liquid transported in the pipeline. Utility Model Content

[0003] In view of the above-mentioned problems existing in the prior art, the purpose of the utility model is to provide a straight pipe with a corrosion-resistant lining. The inner pipe of the corrosion-resistant material covers the inner wall of the outer pipe, the end faces of the socket parts at both ends and the outer wall of the socket parts. When transporting liquid, the parts of the liquid in contact with the pipe are all covered with the corrosion-resistant material, which plays a good anti-corrosion role. The two adjacent straight pipes are connected by double-socket pipe fittings made of corrosion-resistant material. When connected, the inner ring of the sealing ring presses the socket sleeve on the outer wall of the socket part to prevent the inner pipe serving as the lining from falling off, and at the same time prevents the water flow from directly impacting the straight pipe port and causing stratification. The socket sleeve and the inner sleeve are connected by welding, and the welding point is set on the end face of the socket part, which is convenient to manufacture and process, and the weld has no effect on the installation of the pipe. The straight pipe is cylindrical, and the double-socket pipe fitting is short, and both are easy to process and manufacture.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0005] A straight pipe with a corrosion-resistant lining comprises an outer pipe and an inner pipe made of a corrosion-resistant material. The outer pipe has socket parts at both ends and a straight pipe part in the middle. The straight pipe part and the socket part are coaxially connected. The inner pipe covers the inner wall of the outer pipe, the outer walls of the socket parts at both ends of the outer pipe and the end faces of the socket parts. The inner pipe comprises an inner sleeve and two socket sleeves. Both the outer pipe and the inner sleeve are cylindrical. The inner sleeve is sleeved in the outer pipe. The two socket sleeves respectively cover the outer walls of the two socket parts.

[0006] As a further improvement of the above technical solution:

[0007] Two adjacent straight pipes are connected by a double-socket pipe fitting, which is cylindrical. Both ends of the double-socket pipe fitting are socket connection ends. The two socket connection ends are respectively connected to the two adjacent straight pipes. The socket part of one straight pipe is inserted into a socket connection end and sealed by a sealing ring. The outer ring of the sealing ring contacts and presses the inner wall of the socket connection end, and the inner ring of the sealing ring contacts and presses the outer wall of the socket sleeve.

[0008] The double-socket pipe fitting 4 can be made of corrosion-resistant material, or the double-socket pipe fitting 4 can be lined with a connection lining made of corrosion-resistant material. When the double-socket pipe fitting is lined with a connection lining made of corrosion-resistant material, the connection lining is pressed against the inner wall of the double-socket pipe fitting. When a straight pipe and the socket connection end are connected, the outer ring of the sealing ring contacts and presses the inner wall of the connection lining.

[0009] The socket sleeve and the outer wall of the socket part are bonded by hot melt adhesive or glue, or the socket sleeve and the socket part are welded together.

[0010] The thickness of the socket part is equal to the thickness of the straight pipe part, or the sum of the thickness of the socket part and the thickness of the socket sleeve is equal to the thickness of the straight pipe part, or the sum of the thickness of the socket part, the thickness of the socket sleeve and the thickness of the medium between the socket part and the socket sleeve is equal to the thickness of the straight pipe part.

[0011] The outer tube is made of ductile iron or carbon steel.

[0012] The socket sleeve and the inner sleeve are welded together, the welding point is located on the end surface of the socket part, and the part covering the end surface of the socket part is formed by welding after the socket sleeve is flanging and / or the inner sleeve is flanging.

[0013] The thickness of the inner sleeve shall not be less than 0.1mm.

[0014] The straight tube also includes an intermediate layer. The inner sleeve, the intermediate layer and the outer tube are sequentially sleeved from the inside to the outside. The material of the intermediate layer is hot melt adhesive, plastic or rubber.

[0015] When the material of the middle layer is hot melt adhesive, the inner sleeve and the outer tube are bonded together through a composite process; when the material of the middle layer is plastic or rubber, the inner sleeve, the middle layer and the outer tube are pressed together.

[0016] The beneficial effects of the utility model are:

[0017] (1) The inner tube made of corrosion-resistant material covers the inner wall of the outer tube, the end faces of the sockets at both ends, and the outer wall of the sockets, completely isolating the outer tube from the liquid flowing in the tube, effectively preventing the outer tube from rusting, playing a good anti-corrosion role, and extending the service life of the pipe, avoiding the rust of the outer tube from polluting the water quality, and improving the liquid transportation performance.

[0018] (2) Compared with plastic pipe lining, the inner pipe made of corrosion-resistant material has improved surface finish and reduced lining thickness, which improves pipeline water delivery efficiency and reduces operating energy consumption.

[0019] (3) The middle layer also acts as an insulator to prevent the outer tube from contacting the inner tube and causing electrochemical corrosion of the inner tube.

[0020] (4) When two adjacent straight pipes are connected, the socket portion of the straight pipe is inserted into the socket connection end of the double-socket pipe fitting and sealed by a sealing ring. The outer ring of the sealing ring presses the inner wall of the socket connection end, and the inner ring presses the socket sleeve of the outer wall of the socket portion to prevent the inner pipe serving as the lining from falling off, and at the same time prevent the water flow from directly impacting the straight pipe port to cause stratification. At the same time, the liquid contacts corrosion-resistant materials, which has a good anti-corrosion effect and can replace stainless steel pipes, greatly reducing the cost of pipeline materials.

[0021] (5) Compared with the installation method of pipe welding connection, the double socket pipe connection has low requirements on installation conditions and is easy and quick to install. There is a certain deflection angle when the pipe is installed, and it has strong ability to resist geological subsidence.

[0022] (6) When the middle layer is made of hot melt adhesive, the middle layer also plays a connecting role and has a high bonding strength, which prevents the inner tube from being delaminated and deformed under negative pressure. The use of hot melt adhesive as the bonding material eliminates the inner lining delamination caused by the aging of ordinary glue, the uneven glue layer caused by the flow of ordinary liquid glue, the inner lining delamination and electrochemical corrosion caused by the direct contact between the inner lining and the outer tube without bonding. It overcomes the technical problems of low bonding strength, poor hygienic performance, poor insulation effect and uneven inner wall of the outer tube resulting in the lining being suspended (i.e., there are areas of the inner lining that are not bonded to the outer tube) caused by ordinary glue.

[0023] (7) The socket sleeve and the inner sleeve are connected by welding, and the welding point is set on the end face of the socket part, which is convenient for manufacturing and processing, and the weld has no effect on the installation of the pipe.

[0024] (8) The straight pipe is cylindrical and the double-socket pipe is short, and both are easy to process and manufacture. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the straight tube structure when the outer wall of the straight tube portion and the outer wall of the socket sleeve of the first embodiment of the utility model are flush.

[0026] Figure 2 It is a schematic diagram of the straight pipe structure when the thickness of the straight pipe portion and the thickness of the socket portion are equal in Example 1 of the utility model.

[0027] Figure 3 It is a schematic diagram of connecting two adjacent straight pipes in the first embodiment of the utility model.

[0028] Figure 4 It is a schematic diagram of the straight tube structure when the outer wall of the straight tube portion and the outer wall of the socket sleeve of the second embodiment of the utility model are flush.

[0029] Figure 5 This is a schematic diagram of the straight tube structure when the thickness of the straight tube portion and the thickness of the socket portion are equal in Example 2 of the present utility model. DETAILED DESCRIPTION

[0030] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0031] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0032] Embodiment 1

[0033] A straight pipe with a corrosion-resistant lining, such as Figure 1 to Figure 3 As shown, it includes an outer tube 1 and an inner tube 2.

[0034] The outer tube 1 is made of metal, preferably ductile iron or carbon steel. The two ends of the outer tube 1 are the socket parts 11, and the middle part is the straight tube part 12. The straight tube part 12 and the socket part 11 are both cylindrical, and the straight tube part 12 and the socket part 11 share the same center line, that is, the outer tube 1 includes a socket part 11, a straight tube part 12 and another socket part 11 connected in sequence along its axial direction. The inner diameter of the straight tube part 12 is equal to the inner diameter of the socket part 11. One end of the socket part 11 away from the straight tube part 12 is chamfered in the circumferential direction. The straight tube part 12 and the socket part 11 are cast as one piece, or are manufactured separately and then welded together.

[0035] The inner tube 2 is made of a corrosion-resistant material, including but not limited to stainless steel, titanium, and composite materials, preferably stainless steel. The inner tube 2 covers the inner wall of the outer tube 1, the outer wall of the socket part 11 at both ends of the outer tube 1, and the end surface of the socket part 11. Specifically, the inner tube 2 includes an inner sleeve 22 and two socket sleeves 21, and the inner sleeve 22 and the socket sleeve 21 are both cylindrical. The length of the inner sleeve 22 is equal to the length of the outer tube 1, and the outer diameter of the inner sleeve 22 is slightly smaller than the inner diameter of the outer tube 1. The inner sleeve 22 is sleeved in the outer tube 1 and pressed against the inner wall of the outer tube 1.

[0036] The two socket sleeves 21 are respectively sleeved on the outer walls of the two socket parts 11, and the socket sleeves 21 are pressed tightly on the outer wall of the socket part 11. The socket sleeves 21 and the outer wall of the socket part 11 are bonded by hot melt adhesive or glue, or the socket sleeves 21 and the socket part 11 are welded together.

[0037] The socket sleeve 21 and the inner sleeve 22 are welded together, and the welding point is located on the end surface of the socket part 11, that is, the part covering the end surface of the socket part 11 is formed by flanging the socket sleeve 21 and / or flanging the inner sleeve 22 and then welding.

[0038] In summary, the inner sleeve 22 covers the inner wall of the outer tube 1, and the socket sleeve 21 covers the outer wall of the socket part 11. Obviously, the inner sleeve 22 forms the inner lining of the straight tube. The inner tube 2 formed above has no holes and is a continuous medium, which can completely cover the inner wall of the outer tube 1, the end face of the socket part 11 and the outer wall of the socket part 11.

[0039] like Figure 2 As shown, the thickness of the socket portion 11 is equal to the thickness of the straight tube portion 12. After the manufacturing is completed, the socket sleeve 21 protrudes from the outer wall of the straight tube portion 12. Figure 1 As shown, the sum of the thickness of the socket portion 11 and the thickness of the socket sleeve 21, or the sum of the thickness of the socket portion 11, the thickness of the socket sleeve 21, and the thickness of the medium between the socket portion 11 and the socket sleeve 21 is equal to the thickness of the straight tube portion 12. In this way, after manufacturing is completed, the outer wall of the straight tube portion 12 is flush with the outer wall of the socket sleeve 21, the appearance is more beautiful, and the socket portion 11 is not easily damaged during transportation.

[0040] Two adjacent straight pipes are connected by a double socket pipe fitting 4, such as Figure 3 As shown, the double-socket pipe fitting 4 is cylindrical, and both ends of the double-socket pipe fitting 4 are socket connection ends 41, and the two socket connection ends 41 are respectively connected to two adjacent straight pipes. Specifically, the socket portion 11 of one straight pipe is inserted into one socket connection end 41 and sealed by the sealing ring 5. The outer ring of the sealing ring 5 contacts and presses the inner wall of the socket connection end 41, and the inner ring of the sealing ring 5 contacts and presses the outer wall of the socket sleeve 21.

[0041] like Figure 3As shown, on the inner wall of a socket connection end 41, a first step and a second step are sequentially provided in a direction close to the other socket connection end 41. The inner wall of the first step is a cylindrical wall, and the inner wall of the second step is the outer side surface of a truncated cone, that is, from the first step toward the second step, the inner diameter of the second step gradually increases, which is equivalent to a bell mouth. Preferably, the maximum inner diameter of the second step is smaller than the inner diameter of the first step. The bell mouth of the inner wall of the second step is provided to provide a deflection angle for the straight pipe connected thereto, that is, to allow the center line of one of the straight pipes and the center line of the socket connection end 41 connected thereto to be in an intersecting state rather than an overlapping state, in order to allow a certain installation error and facilitate actual operation.

[0042] In order to further improve the corrosion resistance of the straight pipe after connection, the double-socket pipe fitting 4 can be made of corrosion-resistant material, or the double-socket pipe fitting 4 is lined with a connection lining of corrosion-resistant material, and the corrosion-resistant material is preferably stainless steel. The connection lining is pressed against the inner wall of the double-socket pipe fitting 4. When a straight pipe is connected to the socket connection end 41, the outer ring of the sealing ring 5 contacts and presses the inner wall of the connection lining.

[0043] In this embodiment, the inner tube 2 is made of stainless steel, and the thickness of the inner sleeve 22 should not be too large or too small. If the thickness is too large, it will obviously reduce the liquid flow under the same outer tube 1. If the thickness is too small, the welding strength of the inner sleeve 22 is insufficient during welding and the overall deformation is large. The main function of the inner sleeve 22 is corrosion protection. A large number of welding tests have shown that under the conditions of fiber laser welding process, a stainless steel plate with a minimum wall thickness of 0.1mm can obtain a weld with high welding strength and small deformation. Therefore, the thickness range of the inner sleeve 22 is not less than 0.1mm, that is, the minimum thickness of the inner sleeve 22 is 0.1mm. The thickness of the socket sleeve 21 is equal to the thickness of the inner sleeve 22, or the thickness of the socket sleeve 21 is greater than the thickness of the inner sleeve 22, or the thickness of the socket sleeve 21 is less than the thickness of the inner sleeve 22.

[0044] As described above, when two adjacent straight pipes are connected by the double socket pipe fitting 4, the inner and outer rings of the sealing ring 5 can contact the corrosion-resistant material, preventing the straight pipe portion 12 made of ductile iron from partially extending between the sealing ring 5 and the end face of the socket portion 11, causing this part of the straight pipe portion 12 to contact the liquid and rust. At the same time, the socket sleeve 21 is pressed by the sealing ring 5 to fix the inner pipe 2 and prevent the inner pipe 2 from being washed away due to long-term scouring.

[0045] Embodiment 2

[0046] Different from the first embodiment, the present embodiment further includes an intermediate layer 3, and the inner sleeve 22, the intermediate layer 3 and the outer tube 1 are sequentially sleeved from the inside to the outside. The length of the inner sleeve 22, the length of the intermediate layer 3 and the length of the outer tube 1 are equal. The material of the intermediate layer 3 is hot melt adhesive, plastic or rubber.

[0047] When the material of the middle layer 3 is hot melt adhesive, the hot melt adhesive has adhesive properties, and the inner sleeve 22 and the outer tube 1 are bonded together through a composite process. When the material of the middle layer 3 is plastic or rubber, plastic and rubber have no adhesive properties, and the inner sleeve 22, the middle layer 3 and the outer tube 1 are pressed together.

[0048] When the middle layer 3 is a hot melt adhesive, it melts when compounded. When the inner wall of the outer tube 1 is rough, the middle layer melts when heated to fill the pits on the inner wall of the outer tube 1. If the thickness of the middle layer 3 is too small, poor adhesion is likely to occur in areas with large local roughness. At the same time, the middle layer 3 also serves as an insulating layer, and a certain thickness is required to produce an insulating effect between the outer tube 1 and the inner tube 2. The electric spark test and the peel strength test show that when the thickness of the middle layer 3 is not less than 0.2 mm, good peel strength and insulation performance can be stably obtained.

[0049] When the material of the middle layer 3 is plastic and rubber, only the insulation is considered, and the bonding strength does not need to be considered. The electric spark test shows that when the thickness of the middle layer 3 is not less than 0.2 mm, a good insulation performance can be stably obtained.

[0050] Therefore, the thickness range of the inner sleeve 22 is not less than 0.1 mm, that is, the minimum thickness of the inner sleeve 22 is 0.1 mm. The thickness of the middle layer 3 is not less than 0.2 mm.

[0051] Finally, it is necessary to explain here that the above embodiments are only used to further illustrate the technical solution of the utility model in detail and cannot be understood as limiting the protection scope of the utility model. Some non-essential improvements and adjustments made by technicians in this field based on the above content of the utility model belong to the protection scope of the utility model.

Claims

1. A straight pipe with a corrosion-resistant lining, characterized in that: The invention comprises an outer tube (1) and an inner tube (2) made of a corrosion-resistant material. The outer tube (1) has a socket portion (11) at both ends and a straight tube portion (12) in the middle. The straight tube portion (12) and the socket portion (11) are coaxially connected. The inner tube (2) covers the inner wall of the outer tube (1), the outer walls of the socket portions (11) at both ends of the outer tube (1) and the end surface of the socket portion (11). The inner tube (2) comprises an inner sleeve (22) and two socket sleeves (21). Both the outer tube (1) and the inner sleeve (22) are cylindrical. The inner sleeve (22) is sleeved in the outer tube (1). The two socket sleeves (21) respectively cover the outer walls of the two socket portions (11).

2. The straight pipe according to claim 1, characterized in that: Two adjacent straight pipes are connected by a double-socket pipe fitting (4). The double-socket pipe fitting (4) is cylindrical. Both ends of the double-socket pipe fitting (4) are socket connection ends (41). The two socket connection ends (41) are respectively connected to the two adjacent straight pipes. The socket portion (11) of one straight pipe is inserted into a socket connection end (41) and sealed by a sealing ring (5). The outer ring of the sealing ring (5) contacts and presses the inner wall of the socket connection end (41), and the inner ring of the sealing ring (5) contacts and presses the outer wall of the socket sleeve (21).

3. The straight pipe according to claim 2, characterized in that: The double-socket pipe fitting (4) can be made of a corrosion-resistant material, or the double-socket pipe fitting (4) can be sleeved with a connection lining made of a corrosion-resistant material. When the double-socket pipe fitting (4) is sleeved with a connection lining made of a corrosion-resistant material, the connection lining is pressed against the inner wall of the double-socket pipe fitting (4). When a straight pipe is connected to the socket connection end (41), the outer ring of the sealing ring (5) contacts and presses the inner wall of the connection lining.

4. The straight pipe according to claim 1, characterized in that: The socket sleeve (21) and the outer wall of the socket portion (11) are bonded together by hot melt adhesive or glue, or the socket sleeve (21) and the socket portion (11) are welded together.

5. The straight pipe according to claim 4, characterized in that: The thickness of the socket portion (11) is equal to the thickness of the straight tube portion (12), or the sum of the thickness of the socket portion (11) and the thickness of the socket sleeve (21) is equal to the thickness of the straight tube portion (12), or the sum of the thickness of the socket portion (11), the thickness of the socket sleeve (21), and the thickness of the medium between the socket portion (11) and the socket sleeve (21) is equal to the thickness of the straight tube portion (12).

6. The straight pipe according to claim 1, characterized in that: The material of the outer tube (1) is ductile iron or carbon steel.

7. The straight pipe according to claim 1, characterized in that: The socket sleeve (21) and the inner sleeve (22) are welded together, and the welding point is located on the end surface of the socket part (11). The part covering the end surface of the socket part 1 is formed by welding after flanging the socket sleeve (21) and / or flanging the inner sleeve (22).

8. The straight pipe according to claim 1, characterized in that: The thickness of the inner sleeve (22) is not less than 0.1 mm.

9. The straight pipe according to any one of claims 1 to 8, characterized in that: The straight tube further comprises an intermediate layer (3), the inner sleeve (22), the intermediate layer (3) and the outer tube (1) are sequentially sleeved from the inside to the outside, and the material of the intermediate layer (3) is hot melt adhesive, plastic or rubber.

10. The straight pipe according to claim 9, characterized in that: When the material of the middle layer (3) is hot melt adhesive, the inner sleeve (22) and the outer tube (1) are bonded together through a composite process; when the material of the middle layer (3) is plastic or rubber, the inner sleeve (22), the middle layer (3) and the outer tube (1) are pressed together.

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