Inner plastic-coated steel pipe short pipe embedded type connector connecting structure
By designing flared steel pipes and pre-coated plastic short pipes, combined with EPDM sealing rings and epoxy adhesives, the problems of plastic coating damage and sealing during welding of internally coated steel pipes were solved, achieving efficient sealing and simplified construction.
Patent Information
- Application Number
- CN202520805303.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-25
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2035-04-25
AI Technical Summary
Traditional internally coated steel pipes are prone to damage to the coating layer during welding, resulting in poor sealing and complex construction, leading to leakage, water pollution, and high costs.
The design adopts flared steel pipe and pre-coated plastic short pipe. The end of the flared steel pipe is hydraulically cold-flared and formed, and the pre-coated plastic short pipe is embedded to disperse the welding heat. Combined with EPDM sealing ring and epoxy adhesive, a double seal is achieved.
It achieves both protective and efficient sealing with a plastic coating, is compatible with various pipe diameters, simplifies construction, improves efficiency, and reduces costs.
Smart Images
Figure CN223895323U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of water conservancy engineering technology, specifically to an embedded interface connection structure for an internally coated steel pipe short tube. Background Technology
[0002] Internally coated steel pipes are composite pipes made by coating the inner wall of a steel pipe with a layer of plastic material, such as polyethylene or epoxy resin. Traditional welding processes for internally coated steel pipes present the following problems:
[0003] 1. Damage to the plastic coating: The high temperature during welding causes the inner plastic coating to carbonize and fall off, leading to leakage and water pollution.
[0004] 2. Poor sealing performance: Conventional interfaces rely on a single sealing method, resulting in low resistance to seepage pressure.
[0005] 3. Complex construction: The inner plastic coating requires patching, which is inefficient and costly. To address the above problems, the inventors proposed an embedded interface connection structure for short steel pipes with inner plastic coating to solve the above problems. Utility Model Content
[0006] To address the problem that traditional internally coated steel pipes cannot achieve both coating protection and efficient sealing during processing and welding, the purpose of this utility model is to provide an embedded interface connection structure for short internally coated steel pipes.
[0007] To solve the above technical problems, the present invention adopts the following technical solution: an embedded interface connection structure for an internally coated steel pipe short tube, comprising a flared steel pipe and a pre-coated plastic short tube, wherein the outer wall of the pre-coated plastic short tube is provided with a groove, and a sealing ring is embedded in the groove.
[0008] Preferably, there are two flared steel pipes, located on opposite sides of the pre-coated plastic short pipe. The ends of the flared steel pipes are formed by hydraulic cold flaring, with a flaring length of 30mm and an angle of 30°, used to embed into the pre-coated plastic short pipe and disperse welding heat. The end of the flared steel pipe facing the pre-coated plastic short pipe is flared, with a flaring length of 30mm and an angle of 30 degrees. The length of the pre-coated plastic short pipe is 20cm, and the outer wall of the pre-coated plastic short pipe is provided with an annular groove. The inner surface of the pre-coated plastic short pipe is pre-coated with an epoxy resin layer that matches the flared steel pipe. A sealing ring made of EPDM material is embedded in the groove. The sealing ring is used to embed into the groove of the pre-coated plastic short pipe to achieve a physical elastic seal. The height of one side of the groove is equal to the difference between the inner diameter of the large steel pipe and the outer diameter of the small steel pipe, used for centering when embedding the small steel pipe.
[0009] Preferably, both the flared root of the flared steel pipe and the end of the pre-coated plastic short pipe are circumferentially coated with an epoxy adhesive layer. The thickness of the epoxy adhesive layer needs to be greater than 0.2 mm, and the width of the epoxy adhesive layer needs to be greater than 3 mm. When applying the epoxy adhesive layer, the pre-adjusted and welded pre-coated plastic short pipe is uniformly coated with epoxy adhesive along the flared root using a glue gun. The coating thickness is 0.25 mm and the width is 3 mm. Then, the pre-coated plastic short pipe is inserted into the flared steel pipe to the bottom and left to stand for 30 minutes to allow the adhesive to initially solidify. The epoxy adhesive can achieve the first layer of chemical sealing, and the EPDM sealing ring is used to achieve the second layer of physical sealing.
[0010] Compared with the prior art, the advantages of this utility model are as follows: it can achieve plastic coating protection and efficient sealing, and has strong structural adaptability, which can be adapted to various pipe diameters from DN50 to DN600. It also has good sealing performance. The first layer of chemical sealing can be achieved by epoxy adhesive, and the second layer of physical sealing can be achieved by EPDM sealing ring, thus achieving double sealing, which is more reliable. Furthermore, it eliminates the need for joint repair construction of the inner plastic coating, standardizes the prefabrication of short pipes, and enables on-site assembly operations, resulting in higher efficiency. Attached Figure Description
[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model.
[0013] Figure 2 This is a schematic diagram of the flared steel pipe structure of this utility model.
[0014] Figure 3 This is a schematic diagram of the pre-coated plastic short pipe structure of this utility model.
[0015] Figure 4 This is a schematic diagram of the sealing ring structure of this utility model.
[0016] In the diagram: 1. Flared steel pipe; 2. Pre-coated plastic short pipe; 3. Sealing ring; 4. Epoxy adhesive layer; 5. Groove. Detailed Implementation
[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0018] Example: Figure 1-4 As shown, this utility model provides an embedded interface connection structure for an internally coated plastic steel pipe short tube, including a flared steel pipe 1 and a pre-coated plastic short tube 2. The outer wall of the pre-coated plastic short tube 2 is provided with a groove 5, and a sealing ring 3 is embedded in the groove 5.
[0019] There are two flared steel pipes 1, and the two flared steel pipes 1 are located on both sides of the pre-coated plastic short pipe 2.
[0020] By adopting the above technical solution, the end of the flared steel pipe 1 is formed by hydraulic cold flaring, with a flaring length of 30mm and an angle of 30°, which is used to embed the pre-coated plastic short pipe 2 and disperse the welding heat.
[0021] The flared end of the steel pipe 1 facing the pre-coated plastic short pipe 2 is flared, and the flare is 30 mm long and 30 degrees in angle.
[0022] By adopting the above technical solution, the length of the pre-coated plastic short pipe 2 is 20cm. The outer wall of the pre-coated plastic short pipe 2 is provided with an annular groove 5. The inner surface of the pre-coated plastic short pipe 2 is pre-coated with an epoxy resin layer and matches the flared steel pipe 1. A sealing ring 3 is embedded in the groove 5. The sealing ring 3 is made of EPDM material. The sealing ring 3 is used to be embedded in the groove 5 of the pre-coated plastic short pipe 2 to achieve physical elastic sealing. The height of one side of the groove 5 is equal to the difference between the inner diameter of the large steel pipe and the outer diameter of the small steel pipe, which is used for centering when the small steel pipe is embedded.
[0023] The flared root of the flared steel pipe 1 and the end of the pre-coated plastic short pipe 2 are both circumferentially coated with an epoxy adhesive layer 4. The thickness of the epoxy adhesive layer 4 must be greater than 0.2 mm, and the width of the epoxy adhesive layer 4 must be greater than 3 mm.
[0024] By adopting the above technical solution, when applying epoxy adhesive layer 4, the pre-coated plastic short tube 2, which has been pre-adjusted and welded, is evenly coated with epoxy adhesive along the root of the flared end using a glue gun. The coating thickness is 0.25mm and the width is 3mm. Then, the pre-coated plastic short tube 2 is inserted into the flared steel tube 1 to the bottom and left to stand for 30 minutes to allow the adhesive to initially solidify. The epoxy adhesive can achieve the first layer of chemical sealing, and the EPDM sealing ring 3 is used to achieve the second layer of physical sealing.
[0025] Working principle: When using this utility model, firstly, the steel pipe needs to be flared. A hydraulic flaring machine is used to cold flare the end of the steel pipe to form a flared steel pipe 1 with a flaring length of 30mm. The surface must be free of cracks. A pre-coated plastic short pipe 2 can be embedded in the flared part to disperse the welding heat.
[0026] Next, the pre-coated plastic short tube 2 and the sealing ring 3 need to be assembled by pressing the EPDM sealing ring 3 into the groove 5 of the pre-coated plastic short tube 2, and it is necessary to ensure that there is no twisting during installation.
[0027] Then, the pre-coated plastic short pipe 2, which has been pre-adjusted and welded, is evenly coated with epoxy adhesive along the root of the flared end using a glue gun. The coating thickness is 0.25 mm and the width is 3 mm. Next, the pre-coated plastic short pipe 2 is inserted into the flared steel pipe 1 to the bottom and left to stand for 30 minutes to allow the adhesive to initially solidify and form an epoxy adhesive layer 4. The epoxy adhesive can achieve the first layer of chemical sealing, and the EPDM sealing ring 3 is used to achieve the second layer of physical sealing.
[0028] After that, welding is carried out to fix it, that is, welding is performed on the outer steel pipe. When the temperature of the welding joint is transmitted from the middle of the flare to the root of the flare, it has dropped below the failure point of the plastic coating. The temperature can be monitored by an external infrared thermometer, and the monitored temperature is less than or equal to 150℃.
[0029] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.
[0030] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.
Claims
1. An embedded interface connection structure for an internally coated plastic-coated steel pipe short tube, comprising a flared steel pipe (1) and a pre-coated plastic-coated short tube (2), characterized in that: The outer wall of the pre-coated plastic short pipe (2) is provided with a groove (5), and a sealing ring (3) is embedded in the groove (5).
2. The embedded interface connection structure for an internally coated plastic-coated steel pipe short tube as described in claim 1, characterized in that, There are two flared steel pipes (1), and the two flared steel pipes (1) are located on both sides of the pre-coated plastic short pipe (2).
3. The embedded interface connection structure for an internally coated plastic-coated steel pipe short tube as described in claim 1, characterized in that, The flared steel pipe (1) has a flared end facing the pre-coated plastic short pipe (2), and the flared end is 30 mm long and 30 degrees in angle.
4. The embedded interface connection structure for an internally coated plastic-coated steel pipe short tube as described in claim 1, characterized in that, The flared root of the flared steel pipe (1) and the port of the pre-coated plastic short pipe (2) are both circumferentially coated with an epoxy adhesive layer (4).
5. The embedded interface connection structure for an internally coated plastic-coated steel pipe short tube as described in claim 4, characterized in that, The thickness of the epoxy adhesive layer (4) must be greater than 0.2 mm, and the width of the epoxy adhesive layer (4) must be greater than 3 mm.