Steel-plastic conversion pipe fitting manufactured by extruding and coating 3PE (Poly Ethylene) anti-corrosion steel pipe

Abstract

The utility model discloses a steel-plastic conversion pipe fitting manufactured by extruding and coating a 3PE anti-corrosion steel pipe, which comprises a 3PE anti-corrosion steel pipe fitting and a PE plastic part, the outer wall of the 3PE anti-corrosion steel pipe fitting is provided with a plurality of conical inverted tooth structures, and the inner wall of the PE plastic part is embedded into the conical inverted tooth structures. The 3PE anti-corrosion steel pipe fitting is arranged on the outer surface of the seamless steel pipe body, a plastic-coated locking ring is arranged at the joint of the PE anti-corrosion steel pipe fitting and the 3PE anti-corrosion steel pipe fitting in a sleeved mode to form a steel-plastic conversion pipe fitting, the plastic-coated locking ring comprises a steel locking ring, and a polypropylene coating layer is arranged on the outer portion of the steel locking ring, and the 3PE anti-corrosion layer is arranged on the outer surface of the seamless steel pipe body, so that the 3PE anti-corrosion steel pipe is stable in anti-corrosion performance. And the plastic-coated locking ring is provided with the polypropylene coating layer, so that the plastic-coated locking ring has good corrosion resistance, the corrosion resistance of the steel-plastic conversion pipe fitting is excellent, and the corrosion speed of a pipeline is slowed down.

Description

Technical Field

[0001] This utility model relates to the field of gas pipe fittings technology, specifically to a steel-plastic conversion pipe fitting made of extruded 3PE anti-corrosion steel pipe. Background Technology

[0002] Steel-plastic conversion pipe fittings are one of the main connecting components in the installation and construction of polyethylene plastic gas pipelines. Small-diameter steel-plastic conversion pipe fittings are generally used as gas inlet pipes in courtyards to connect underground PE pipes with above-ground steel pipes. However, they are usually located at the corner of the wall where the pipes exit the ground, which is a humid and oxygen-rich environment. Moisture can easily penetrate and adhere to the surface of the steel pipe, causing the pipe to corrode quickly and often leading to pipe perforation.

[0003] Therefore, this utility model proposes a plastic conversion pipe fitting made of extruded 3PE anti-corrosion steel pipe, which has stable anti-corrosion properties. Summary of the Invention

[0004] In view of the problems existing in the prior art, the purpose of this utility model is to provide a plastic conversion pipe fitting made of extruded 3PE anti-corrosion steel pipe, which has the characteristics of excellent anti-corrosion performance.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A steel-plastic conversion pipe fitting made from extruded 3PE anti-corrosion steel pipe includes a 3PE anti-corrosion steel pipe fitting and a PE plastic part. The outer wall of the 3PE anti-corrosion steel pipe fitting has several tapered inverted tooth structures. The inner wall of the PE plastic part is embedded in the tapered inverted tooth structures through an interference fit extrusion. A plastic-coated locking ring is sleeved at the connection between the PE anti-corrosion steel pipe fitting and the 3PE anti-corrosion steel pipe fitting, thus forming a steel-plastic conversion pipe fitting. The plastic-coated locking ring includes a steel locking ring, and the outside of the steel locking ring is covered with a polypropylene coating layer.

[0007] Furthermore, the 3PE anti-corrosion steel pipe fitting includes a seamless steel pipe body, the outer surface of which is provided with a 3PE anti-corrosion layer, and the end of the seamless steel pipe body that mates with the PE plastic pipe fitting is rounded to avoid damaging the PE plastic fitting during press fitting.

[0008] Furthermore, the end of the seamless steel pipe body away from the PE plastic part is provided with a V-shaped bevel or processed into a standard thread.

[0009] Furthermore, a sealing groove is provided between the rounded corner treatment and the conical tooth structure, and a sealing ring is installed in the sealing groove.

[0010] Furthermore, the 3PE anti-corrosion layer includes a fusion-bonded epoxy powder coating, an adhesive layer, and a polyethylene layer from the inside out, and a double-sloped transition step is provided at the joint between the 3PE anti-corrosion layer and the seamless steel pipe body.

[0011] Furthermore, the steel locking ring has bevels at both ends for securing the polypropylene coating layer.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] 1) The outer surface of the seamless steel pipe body of this utility model is provided with a 3PE anti-corrosion layer. The 3PE anti-corrosion layer includes a fusion-bonded epoxy powder coating, an adhesive layer and a polyethylene layer from the inside to the outside. The anti-corrosion performance of the 3PE anti-corrosion steel pipe is very stable, with no excess glue and no gaps at the ends. The plastic-coated locking ring includes a steel locking ring with a polypropylene coating layer on the outside, which makes the plastic-coated locking ring have good anti-corrosion properties. This makes the steel-plastic conversion pipe fitting have excellent anti-corrosion performance and slows down the corrosion rate of the pipeline.

[0014] 2) This utility model makes the steel locking ring more scratch-resistant by providing a polypropylene coating layer on the outside of the steel locking ring;

[0015] 3) This utility model has several tapered reverse teeth structure on the outer surface of the seam steel pipe body and the PE anti-corrosion steel pipe fitting, which has a pull-out resistance after press fitting;

[0016] 4) A sealing groove is provided between the arc corner treatment and the conical tooth structure at the joint between the seamless steel pipe body and the PE anti-corrosion steel pipe fitting. A sealing ring is installed in the sealing groove to make the connection and fit better and ensure that there is no air leakage. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the extruded 3PE anti-corrosion steel-plastic conversion pipe fitting of this utility model;

[0018] Figure 2 This is a schematic diagram of the cross-section of the extruded 3PE anti-corrosion steel pipe of this utility model;

[0019] Figure 3 This is a schematic diagram of the 3PE anti-corrosion steel pipe fitting of this utility model;

[0020] Figure 4 This is a schematic diagram of the plastic-coated locking ring of this utility model;

[0021] Figure 5 This is a schematic diagram of the PE plastic part of this utility model;

[0022] Figure 6 This is Embodiment 1 of the present invention: a straight-pipe 3PE anti-corrosion steel-plastic conversion pipe fitting;

[0023] Figure 7 This is Embodiment 2 of the present invention, a bent-pipe type 3PE anti-corrosion steel-plastic conversion pipe fitting.

[0024] In the diagram: 1. 3PE anti-corrosion steel pipe fittings; 11. Rounded corner treatment; 12. Sealing groove; 13. Conical toothed structure; 14. Double-sloped transition step; 15. Seamless steel pipe body; 16. 3PE anti-corrosion layer; 17. Fusion-bonded epoxy powder coating; 18. Adhesive layer; 19. Polyethylene layer; 20. V-shaped bevel; 2. PE plastic parts; 21. Steel-plastic joint; 22. Pipe; 3. Plastic-coated locking ring; 31. Steel locking ring; 311. Bevel; 32. Polypropylene coating layer; 4. Sealing ring. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the scope described herein.

[0026] like Figure 1 and 5 As shown, a steel-plastic conversion pipe fitting made of extruded 3PE anti-corrosion steel pipe includes a 3PE anti-corrosion steel pipe fitting 1 and a PE plastic part 2. The outer wall of the 3PE anti-corrosion steel pipe fitting 1 has several tapered inverted tooth structures 13. In order to have a pull-out resistance after press fitting, the inner wall of the PE plastic part 2 is embedded in the tapered inverted tooth structure 13. A plastic-coated locking ring 3 is sleeved at the connection between the PE plastic part 2 and the 3PE anti-corrosion steel pipe fitting 1, thus forming a steel-plastic conversion pipe fitting.

[0027] The PE plastic part 2 is injection molded to ensure the long service life and overall performance of the steel-plastic conversion. Before pressing, the wall thickness of the PE body at the steel-plastic joint 21 should be at least 1.25 times the nominal wall thickness corresponding to the nominal outer diameter of the pipe 22 connected to it.

[0028] At the steel-plastic joint, the PE wall thickness of section 21 should be greater than the difference between the inner diameter of the plastic-coated locking ring 3 and the outer diameter of the connection point of the 3PE anti-corrosion steel pipe fitting 1, to ensure an interference fit. The opening of the PE plastic part at the steel-plastic joint needs to have an inner chamfer so that it can be compacted and sealed with the double-sloped transition step machined on the 3PE steel pipe fitting, preventing it from tipping over.

[0029] Please refer to Figure 4 The plastic-coated locking ring 3 includes a steel locking ring 31, and the steel locking ring 31 is covered with a polypropylene coating layer 32. The polypropylene coating layer 32 solves the corrosion problem of the steel locking ring and also makes the plastic-coated locking ring 3 scratch-resistant.

[0030] 3PE anti-corrosion steel pipe fittings 1 have good corrosion resistance and a steel locking ring 31 with a polypropylene coating 32 on the outside, which makes the steel-plastic conversion pipe fittings have excellent anti-corrosion performance, slows down the corrosion rate of the pipeline, and avoids the occurrence of pipeline perforation.

[0031] The steel locking ring 31 has bevels 311 at both ends for securing the polypropylene coating layer 32, which facilitates the securing of the plastic layer; the steel locking ring 31 is flat and smooth in the middle so that it can be inserted into the core of the mold for external plastic injection.

[0032] Please refer to Figure 3 The 3PE anti-corrosion steel pipe fitting 1 includes a seamless steel pipe body 15, the outer surface of which is provided with a 3PE anti-corrosion layer 16. Please refer to [reference needed]. Figure 2 The 3PE anti-corrosion layer 16 includes a fusion-bonded epoxy powder coating 17, an adhesive layer 18, and a polyethylene layer 19, which are arranged from the inside out.

[0033] The 3PE anti-corrosion layer 16 and the seamless steel pipe body 15 are provided with a double-sloped transition step 14. During press-fitting, the PE plastic part covers this part to achieve sealing and prevent the steel pipe from being exposed to the air after machining.

[0034] The ends of the seamless steel pipe body 15 that mate with the PE plastic parts 2 are rounded 11 to prevent damage to the PE plastic parts 2 during press-fitting.

[0035] The seamless steel pipe body 15 has a V-groove 20 at the end away from the PE plastic part 2 for easy welding during use; or it can be machined into threads for easy threaded connection during use. The V-groove 20 conforms to the V-groove of GB 50236.

[0036] A sealing groove 12 is provided between the rounded corner treatment 11 and the tapered tooth structure 13 for installing the sealing ring 4. After pressing, the seal is maintained by the elasticity of the compressed rubber.

[0037] 3PE anti-corrosion steel pipe fitting 1 is made by extruding seamless steel pipe coated with 3PE anti-corrosion, machining it, and then pressing it.

[0038] Production process of extruded coated 3PE anti-corrosion steel pipe:

[0039] Seamless steel pipe → through shot blasting → medium frequency induction heating → electrostatic spraying of fusion bonded epoxy powder → medium frequency induction heating curing → extrusion coating of adhesive layer → extrusion coating of polyethylene layer → spray cooling.

[0040] For radiation cross-linked polyethylene heat shrink sleeve repair and corrosion protection, extrusion coating of 3PE corrosion protection is carried out in an extruder by heating and pressurizing polyethylene and adhesive in a flowing state to form a PE anti-corrosion layer on the pipeline through an extrusion die. The production process has strong continuity, making the performance of 3PE anti-corrosion steel pipe fittings more stable. The anti-corrosion layer has high adhesion to the inner bare steel pipe, is resistant to peeling, and has better anti-corrosion performance.

[0041] As a second embodiment of this utility model, such as Figure 7 As shown, if a bendable steel-plastic conversion pipe fitting is required, in such cases... Figure 6The straight-pipe 3PE anti-corrosion steel-plastic conversion pipe fitting shown in Embodiment 1 can be bent in the final process to make a bent-pipe steel-plastic conversion pipe fitting.

Claims

1. A steel-plastic conversion pipe fitting made from extruded 3PE anti-corrosion steel pipe, characterized in that... The system includes a 3PE anti-corrosion steel pipe fitting (1) and a PE plastic part (2). The outer wall of the 3PE anti-corrosion steel pipe fitting (1) is provided with several tapered inverted tooth structures (13). The inner wall of the PE plastic part (2) is embedded in the tapered inverted tooth structure (13) through an interference fit extrusion. A plastic-coated locking ring (3) is provided at the connection between the PE plastic part (2) and the 3PE anti-corrosion steel pipe fitting (1), thus forming a steel-plastic conversion pipe fitting. The plastic-coated locking ring (3) includes a steel locking ring (31), and the steel locking ring (31) is provided with a polypropylene coating layer (32) on the outside.

2. A steel-plastic conversion pipe fitting made from extruded 3PE anti-corrosion steel pipe according to claim 1, characterized in that... The 3PE anti-corrosion steel pipe fitting (1) includes a seamless steel pipe body (15), the outer surface of the seamless steel pipe body (15) is provided with a 3PE anti-corrosion layer (16), and the end of the seamless steel pipe body (15) that mates with the PE plastic part (2) is rounded (11) to avoid damaging the PE plastic part (2) during press fitting.

3. A steel-plastic conversion pipe fitting made from extruded 3PE anti-corrosion steel pipe according to claim 2, characterized in that... The seamless steel pipe body (15) has a V-shaped bevel (20) or is processed into a standard thread at the end away from the PE plastic part (2).

4. A steel-plastic conversion pipe fitting made from extruded 3PE anti-corrosion steel pipe according to claim 2, characterized in that... A sealing groove (12) is provided between the rounded corner treatment (11) and the conical tooth structure (13), and a sealing ring (4) is installed in the sealing groove (12).

5. A steel-plastic conversion pipe fitting made from extruded 3PE anti-corrosion steel pipe according to claim 2, characterized in that... The 3PE anti-corrosion layer (16) includes a fusion-bonded epoxy powder coating (17), an adhesive layer (18), and a polyethylene layer (19) from the inside out. The 3PE anti-corrosion layer (16) and the seamless steel pipe body (15) are provided with a double-sloped transition step (14).

6. A steel-plastic conversion pipe fitting made from extruded 3PE anti-corrosion steel pipe according to claim 2, characterized in that... The steel locking ring (31) has bevels (311) at both ends for fastening the polypropylene coating layer (32).

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