A corrosion-resistant pipe structure

Abstract

This utility model relates to the technical field of pipe materials, specifically to a corrosion-resistant pipe structure, including an upper pipe and a lower pipe arranged in a matching manner. An anti-corrosion component is fitted at the junction of the upper and lower pipes. The anti-corrosion component includes a protective outer shell and an inner sealing layer. A first support and a second support are fixedly connected to the outer surface of the protective outer shell. A sealing groove is formed on the inner surface of the sealing layer, and a contact layer is embedded in the sealing groove. A positioning groove is formed on the surface of the protective outer shell, connecting the sealing groove and the sealing layer. The two sets of hemispherical protective outer shells form a spherical shape fitted at the junction of the upper and lower pipes, effectively preventing the residue of external corrosive liquids at the pipe junction. The positioning groove ensures the positioning and splicing of the two sets of protective outer shells, and the first and second supports provide a limiting and fixing effect on the two sets of spliced ​​protective outer shells from the outside.

Description

Technical Field

[0001] This utility model relates to the technical field of pipes, specifically to a corrosion-resistant pipe structure. Background Technology

[0002] In fields such as chemical engineering, marine engineering, and wastewater treatment, corrosion protection of metal pipeline welds is crucial. Traditional corrosion protection solutions typically employ the following two methods:

[0003] Metal protective covers (such as stainless steel and Hastelloy): Although resistant to high temperature and pressure, they pose a risk of galvanic corrosion (caused by the potential difference with carbon steel pipes to trigger a galvanic cell reaction), are heavy (density > 7.9 g / cm³), require heavy support for installation, and are costly (accounting for 30%-40% of the total cost of the piping system).

[0004] Non-metallic sealing sleeves (such as pure rubber and plastic): Lightweight materials (such as unreinforced polyethylene) have insufficient mechanical strength (tensile strength <20MPa) and are prone to failure due to pipeline vibration and deformation. When glass fiber comes into direct contact with metal pipes, the silicate components in the fiber may accelerate local corrosion (poor electrochemical compatibility).

[0005] Problems with existing technology:

[0006] Metal solutions are costly, non-metal solutions have short lifespans, and there is a lack of lightweight designs that balance economy and long-term corrosion protection.

[0007] The interface between the protective components and the pipeline is prone to micro-gaps due to thermal expansion and contraction, which can cause corrosive media to penetrate into the weld. Utility Model Content

[0008] To address the shortcomings of existing technologies, this utility model provides a corrosion-resistant pipe structure that can solve the following problems:

[0009] Metal solutions are costly, while non-metal solutions have short lifespans, and there is a lack of lightweight designs that balance cost-effectiveness with long-term corrosion protection.

[0010] The interface between the protective components and the pipeline is prone to micro-gaps due to thermal expansion and contraction, which can lead to the penetration of corrosive media into the weld.

[0011] To solve the above-mentioned technical problems, the present invention proposes the following technical solution:

[0012] A corrosion-resistant pipe structure includes an upper pipe and a lower pipe, with an anti-corrosion component sleeved at the junction of the upper and lower pipes. The anti-corrosion component includes:

[0013] Protective outer shell: It is composed of two sets of longitudinally opposite hemispherical shells spliced ​​together, and its inner wall is trapezoidal and concave;

[0014] Sealing layer: Located inside the protective shell, it is semi-cylindrical in shape and has a trapezoidal vertical section;

[0015] Sealing groove: It is formed on the inner wall of the sealing layer and extends in an arc shape;

[0016] Contact layer: Embedded in the sealing groove, it is curved in an arc and fits the pipe joint surface;

[0017] Positioning groove: It is opened on both sides of a set of vertical sectional surfaces of the protective shell, and includes three staggered arc-shaped grooves;

[0018] Arc-shaped retaining strip: Set on the vertical section surface of another set of protective shells, and fits into the positioning groove;

[0019] The first and second supports are fixed to the outside of the protective shell and are symmetrically distributed on the upper and lower sides and the curved surfaces on both sides.

[0020] Furthermore, the protective shell has a through-cavity with concave arc edges at its upper and lower ends and sealing rings. The sealing rings are made of glass fiber filled polyethylene, with medium-density polyethylene (MDPE) as the base material and 15% chopped glass fiber as filler. The ring stiffness is ≥10MPa.

[0021] Furthermore, the protective outer shell is made of glass fiber reinforced polyethylene (FRPE), with a high-density polyethylene (HDPE) matrix containing 30% glass fiber reinforcement, and its inner wall is sprayed with polyethylene anti-corrosion slurry.

[0022] Furthermore, the first support is a rectangular convex structure with a strip-shaped threaded opening on the surface. Its bolt holes are pre-embedded with stainless steel threaded inserts and covered with a PE layer. The second support is an arc-shaped convex structure with threaded holes on the surface. Nylon bushings are embedded in the holes. The first support, the second support, and the protective shell are integrally molded as FRPE material.

[0023] Furthermore, the sealing layer is made of cross-linked polyethylene with a compression set of <15%, the contact layer is a polyethylene / PTFE composite tape, the base layer is ultra-high molecular weight polyethylene, and the surface is laminated with a 0.2mm PTFE film.

[0024] Furthermore, the protective shell is positioned by fitting with the arc-shaped clip through the positioning groove. The two sets of protective shells are connected to the first and second supports by external screws. The screws are made of 316 stainless steel and covered with polyethylene heat shrink sleeves.

[0025] As can be seen from the above technical solution, the beneficial effects of this utility model are:

[0026] 1. This utility model consists of two sets of hemispherical protective shells that are spherically fitted onto the joint of upper and lower pipes. This effectively prevents external corrosive liquids from remaining at the pipe joint. The positioning groove ensures the positioning and splicing of the two sets of protective shells. The first and second supports limit and fix the spliced ​​protective shells from the outside. The sealing rings that run through the upper and lower edges of the chamber in the protective shells help ensure the sealing of the anti-corrosion components and the pipe fitting position, preventing external corrosive substances from entering between the pipe and the anti-corrosion components. The trapezoidal concave inner wall of the protective shell helps ensure its fit and positioning with the sealing layer.

[0027] 2. This device uses glass fiber reinforced polyethylene (FRPE) instead of metal shell, with 30% glass fiber to increase strength (tensile strength ≥80MPa), and utilizes the acid and alkali resistance of polyethylene matrix (pH 1-12) to block corrosion. The sealing layer uses cross-linked polyethylene (XLPE), and the cross-linked network density improves the medium barrier properties (compression set <15%). The contact layer is designed as a UHMWPE+PTFE composite tape, with a 0.2mm PTFE film to isolate highly corrosive media, and the UHMWPE base layer to ensure toughness.

[0028] 3. In this utility model, the trapezoidal concave inner wall of the protective shell and the trapezoidal cross section of the sealing layer achieve self-locking and tight fit, eliminating thermal deformation gaps. A glass fiber filled MDPE sealing ring (ring stiffness ≥10MPa) is set through the edge of the cavity to adapt to the micro displacement of the pipeline. The pre-embedded metal parts of the support are fully covered and isolated (PE layer / nylon bushing), eliminating any metal exposure.

[0029] 4. This utility model avoids galvanic corrosion throughout the entire system (no exposed metal / pure glass fiber components), reduces weight by 60%, and reduces cost by 45%-50%. It is suitable for low-temperature corrosive environments at normal pressure (-30℃~80℃). Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0031] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0032] Figure 2 This is a schematic diagram of the connection of the anti-corrosion components in this utility model;

[0033] Figure 3 This is a schematic diagram of the connection of the protective shell in this utility model.

[0034] Figure label:

[0035] 1. Upper pipe; 2. Lower pipe; 3. Corrosion-resistant components; 4. Protective housing; 5. First support; 6. Second support; 7. Sealing layer; 8. Contact layer; 9. Sealing groove; 10. Positioning groove. Detailed Implementation

[0036] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0037] See Figure 1-3 As shown, a corrosion-resistant pipe structure includes an upper pipe 1 and a lower pipe 2 that are matched and installed at the top and bottom. An anti-corrosion component 3 is fitted at the junction of the upper pipe 1 and the lower pipe 2. The anti-corrosion component 3 includes a protective shell 4 and an inner sealing layer 7. A first support 5 and a second support 6 are fixedly connected to the outer surface of the protective shell 4. A sealing groove 9 is opened on the inner surface of the sealing layer 7. A contact layer 8 is embedded in the sealing groove 9. A positioning groove 10 is opened on the surface of the protective shell 4. The sealing groove 9 and the sealing layer 7 are connected.

[0038] In this embodiment of the invention, the protective shell 4 is a hemispherical shell with two sets arranged longitudinally opposite each other. Positioning grooves 10 are arc-shaped and opened on both sides of the vertical cross-sectional surface of one set of protective shells 4. The positioning grooves 10 are distributed in two sets, and one set includes three staggered arc-shaped grooves. The vertical cross-sectional surface of the other set of protective shells 4 is provided with raised arc-shaped retaining strips corresponding to the positioning grooves 10. The protective shell 4 has through chambers corresponding to the upper and lower pipes from top to bottom, and the upper and lower edges of the through chambers are arc-shaped and concave. Sealing rings are provided on the inner sides of the upper and lower ends, and the sealing rings are made of glass fiber filled polyethylene. The matrix is ​​medium-density polyethylene (MDPE) and filled with 15% chopped glass fiber. During use, the ring stiffness is increased to ≥10MPa, effectively adapting to the micro-deformation of the pipeline. The inner wall of the protective shell 4 is trapezoidally concave and is made of glass fiber reinforced polyethylene (FRPE). The matrix is ​​high-density polyethylene (HDPE) and is reinforced with 30% glass fiber. The inner wall of the shell is sprayed with polyethylene anti-corrosion slurry. In actual use, it has a tensile strength of ≥80MPa, is resistant to acids and alkalis (pH 1-12), and the polyethylene anti-corrosion slurry sprayed on the inner wall can effectively enhance the corrosion resistance of the sealing surface.

[0039] The first support 5 is rectangular and protruding, symmetrically distributed on the upper and lower sides of the protective shell 4, with a strip-shaped threaded opening on its surface. The second support 6 is arc-shaped and protruding, distributed on both sides of the arc-shaped surface of the protective shell 4, with threaded holes on its surface. Both the first support 5 and the second support 6, like the protective shell, are made of FRPE. The bolt holes of the first support 5 have embedded stainless steel threaded inserts and are covered with a PE layer to isolate corrosion, while the threaded holes of the second support 6 have embedded nylon bushings to prevent metal exposure. The two sets of protective shells 4, arranged in hemispherical shells, form a spherical sleeve that fits over the joint of the upper and lower pipes. The positioning effectively prevents external corrosive liquids from remaining at the pipe joint. The positioning groove 10 ensures the positioning and splicing of the two sets of protective shells 4. The first support 5 and the second support 6 limit and fix the two sets of spliced ​​protective shells 4 from the outside. The sealing ring set through the upper and lower edges of the chamber in the protective shell 4 helps to ensure the sealing of the anti-corrosion component 3 and the pipe sleeve position, preventing external corrosive substances from entering between the pipe and the anti-corrosion component 3. The trapezoidal concave inner wall of the protective shell 4 helps to ensure its fit and positioning with the sealing layer 7.

[0040] The sealing layer 7 is arranged in two sets in a semi-cylindrical shape with longitudinal opposite orientation. Its vertical section is trapezoidal. The sealing groove 9 is opened in an arc shape along the inner wall of the sealing layer 7. The contact layer 8 is also curved along the sealing groove 9. The contact layer 8 is attached to the surface of the upper and lower pipes at the joint. The sealing layer 7 is made of cross-linked polyethylene (XLPE), which has been chemically cross-linked to increase its density. In actual use, it is resistant to weak acids / alkalis (such as 20% H2SO4, 10% NaOH). Its elastic modulus is >500MPa (compression set <15%).

[0041] The contact layer 8 is set as a polyethylene / PTFE composite tape, with ultra-high molecular weight polyethylene (UHMWPE) as the base layer and a 0.2mm PTFE film on the surface. During use, the inertness of PTFE can block strong corrosive media, while UHMWPE provides the toughness of the substrate.

[0042] When using this device, after the upper and lower pipes are welded, one half of the protective shell 4 is attached to one side of the pipe welding position, and the other half of the protective shell 4 is attached to the other side of the pipe welding position. The first support 5 on the surface of the two sets of protective shells 4 is connected and fixed by external screws (made of 316 stainless steel with polyethylene heat shrink sleeve on the surface to completely isolate the medium). Then the second support 6 on the surface of the two sets of protective shells 4 is connected and fixed. During use, the sealing layer 7 and contact layer 8 inside the protective shell 4 can effectively prevent external corrosive substances from contacting the pipe welding position.

[0043] In this device, glass fiber is used only as a reinforcing phase in the FRPE protective shell 4 and the sealing ring to solve the problem of insufficient rigidity of pure PE and does not directly contact the corrosive medium.

[0044] Pure fiberglass components should not be used to avoid galvanic corrosion with metal pipes.

[0045] The glass fiber in the sealing shell 4 and sealing ring enhances the structural strength, while the PE matrix provides chemical corrosion protection. The XLPE cross-linked network in the sealing layer 7 blocks the penetration of the medium and has better corrosion resistance than ordinary PE. The contact layer 8 is a UHMWPE+PTFE composite, sacrificing the absolute corrosion resistance of PTFE in exchange for cost balance.

[0046] All bolts and inserts in this device are covered with PE or isolated with nylon to ensure zero contact with corrosive media.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A corrosion resistant pipe construction comprising an upper pipe (1) and a lower pipe (2), characterized in that: A corrosion-resistant component (3) is fitted at the junction of the upper pipe (1) and the lower pipe (2), and the corrosion-resistant component (3) includes: Protective outer shell (4): It is composed of two sets of longitudinally opposite hemispherical shells spliced ​​together, and its inner wall is trapezoidal concave; Sealing layer (7): Located inside the protective shell (4), it is semi-cylindrical and has a trapezoidal vertical section; Sealing groove (9): It is formed on the inner wall of the sealing layer (7) and extends in an arc shape; Contact layer (8): Embedded in the sealing groove (9), it is curved in an arc and fits the pipe joint surface; Positioning groove (10): It is opened on both sides of the vertical section surface of a set of protective shells (4), and includes three staggered arc grooves; Arc-shaped retaining strip: set on the vertical section surface of another set of protective shells (4), and fitted into the positioning groove (10); The first support (5) and the second support (6) are fixed to the outside of the protective shell (4) and are symmetrically distributed on the upper and lower sides and the arc-shaped surfaces on both sides.

2. The corrosion resistant tubular structure of claim 1, wherein: The protective shell (4) has a through-cavity, with its upper and lower edges arc-shaped and recessed and equipped with sealing rings. The sealing rings are made of glass fiber filled polyethylene, and the matrix is ​​medium-density polyethylene containing short-cut glass fibers.

3. The corrosion resistant tubular structure of claim 1, wherein: The protective shell (4) is made of glass fiber reinforced polyethylene, the matrix is ​​high-density polyethylene, and contains glass fiber. Its inner wall is sprayed with polyethylene anti-corrosion slurry.

4. The corrosion resistant tubular structure of claim 1, wherein: The first support (5) is a rectangular convex structure with a strip-shaped threaded opening on the surface. Its bolt hole is pre-embedded with a stainless steel threaded insert and covered with a PE layer. The second support (6) is an arc-shaped convex structure with a threaded hole on the surface. A nylon bushing is embedded in the hole. The first support (5), the second support (6), and the protective shell (4) are integrally formed.

5. The corrosion resistant pipe construction of claim 1, wherein: The sealing layer (7) is made of cross-linked polyethylene, the contact layer (8) is a polyethylene / PTFE composite tape, the base layer is ultra-high molecular weight polyethylene, and the surface is composited with a 0.2mm PTFE film.

6. The corrosion resistant pipe construction of claim 1, wherein: The protective shell (4) is positioned by fitting the arc-shaped clip with the positioning groove (10). The two sets of protective shells (4) are connected to the first support (5) and the second support (6) by external screws. The screws are made of 316 stainless steel and are covered with polyethylene heat shrink sleeve.

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