Lining non-metal composite steel pipe joint device with double-sealing structure

Abstract

The invention discloses a lining non-metal composite steel pipe joint device with a double-sealing structure. The joint device comprises two steel flanges connected with the ends of steel base pipes in two lining non-metal composite steel pipes correspondingly, a corrosion-resistant alloy pressing ring, a sealing gasket and a fixing part. The two steel flanges are oppositely arranged, and first grooves are formed in the middles of the sealing faces of the two steel flanges correspondingly. The fixing component fixes the two steel flanges through bolt holes in the outer edges of the steel flanges. The corrosion-resistant alloy pressing ring is arranged in the first groove; the sealing gasket is arranged between the two steel flanges and located on the inner edges of the steel flanges. By the adoption of the structure, double sealing of the lining non-metal composite steel pipe connector is achieved, the field leakage risk is reduced, and the advantages of being easy to operate and rapid to install are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of lined non-metallic composite steel pipe joints, and in particular to a lined non-metallic composite steel pipe joint device with a double sealing structure and an installation method. Background Art

[0002] Problems such as corrosion, scaling, and wax deposition in gathering and transportation pipelines are important issues faced by many oilfield production. In order to solve these problems, using lined non-metallic composite steel pipes as ground pipelines is a good choice. Lined non-metallic composite steel pipes are to install non-metallic lining pipes on the inner wall of steel base pipes, forming an interference fit between the steel pipe and the lining pipe to improve their bonding strength. The steel base pipe provides strength support for the composite pipe, while the non-metallic lining pipe improves the corrosion resistance, anti-scaling, and drag reduction properties of the steel pipe. Currently, the commonly used non-metallic lining materials mainly include plastic materials such as polyethylene and polypropylene. Among them, high-density polyethylene and ultra-high molecular weight polyethylene are widely used, especially ultra-high molecular weight polyethylene lined pipes, which have good wear resistance, toughness, and resistance to acid, alkali and various salt corrosion. The application of more and more widely used in gathering and transportation pipelines.

[0003] For the gathering and transportation pipeline lined with non-metallic composite steel pipes, the connection joints are the key parts for the leakage of the medium in the pipeline and the corrosion of the pipeline. The quality of the connection joints and their sealing effect are the key factors affecting the service life of the pipeline. At present, the connection methods of the joints of the lined non-metallic composite steel pipes mainly include welding, clamp connection, flange connection, etc. However, these connection methods have various problems. For the welded lined non-metallic composite steel pipes, the on-site welding joints can use internal anti-corrosion patching or UB bushing technology to carry out internal anti-corrosion on the joints. However, due to the generally small diameter of the gathering and transportation pipelines, the internal anti-corrosion patching technology is difficult to construct, the cost is high, and the quality control is difficult; and for the joints lined with UB bushings for anti-corrosion, it is difficult to inspect the bonding quality of the UB bushing and the inner lining layer, and there is a risk of burning of the UB bushing during the subsequent welding process. Therefore, the medium in the pipeline is easy to enter the interface between the base pipe and the liner from the poor bonding or the liner burnt part, causing corrosion of the base pipe. In addition, currently, clamp and flange connection are commonly used connection methods for lined non-metallic composite steel pipes. By tightening the clamp or bolt, the pipe end flange is pressed against the lining flange, so that the flange lining materials and sealing rings on both sides of the joint fit tightly to achieve a sealing effect. However, in actual operation, due to the influence of factors such as mechanical assembly errors and irregular construction operations, the size of the clamp and bolt tightening force is difficult to guarantee, and the sealing effect of the pipe end lining cannot be guaranteed. When the surface of the flange lining material is damaged, these damaged parts are very likely to become channels for the leakage of the medium in the pipeline.

[0004] Therefore, it is urgent to develop a sealing structure with good sealing effect, which can not only ensure that the medium in the pipeline does not leak and does not contact the steel base pipe, but also ensure the connection strength of the joint, facilitate on-site installation, and have a low overall cost to meet the needs of on-site use. Summary of the invention

[0005] The purpose of the present invention is to provide a lined non-metallic composite steel pipe joint device with a double sealing structure. The device has a good sealing effect, which can not only ensure that the medium in the pipeline does not leak and does not contact the steel base pipe, but also ensure the connection strength of the joint, which is convenient for on-site installation.

[0006] To achieve the above object, the present invention provides a lined non-metallic composite steel pipe joint device with a double sealing structure, the joint device comprising: two steel flanges respectively connected to the ends of the steel base pipes in two lined non-metallic composite steel pipes, a corrosion-resistant alloy pressure ring, a sealing gasket and a fixing component;

[0007] The two steel flanges are arranged opposite to each other, and a first groove is respectively arranged in the middle of the sealing surfaces of the two steel flanges; the fixing component fixes the two steel flanges through the bolt holes on the outer edges of the steel flanges; the corrosion-resistant alloy pressure ring is arranged in the first groove; the sealing gasket is arranged between the two steel flanges and located at the inner edge of the steel flanges.

[0008] Optionally, the lined non-metallic composite steel pipe also includes: a non-metallic lining pipe inserted into the steel base pipe, and a non-metallic lining pipe of a predetermined length is retained at the pipe end of the lined non-metallic composite steel pipe, and the non-metallic lining pipe with a predetermined length is flanging-processed to form a non-metallic covering layer covering the corresponding steel flange sealing surface.

[0009] Optionally, the second groove and the flange step are formed respectively by pressing the non-metallic covering layers on the sealing surfaces of the two steel flanges;

[0010] Correspondingly, the corrosion-resistant alloy pressure ring is arranged in the second groove; and the sealing gasket is arranged at the step of the flanging step.

[0011] Optionally, the non-metallic liner pipe is a non-metallic pipe made of polyethylene or polypropylene.

[0012] Optionally, the joint device further comprises a weld for connecting the end of the steel base pipe and the steel flange.

[0013] Optionally, the steel flange is a neck-welded flange.

[0014] Optionally, the fixing component includes: a component consisting of a bolt and a nut.

[0015] Optionally, the material of the corrosion-resistant alloy pressure ring is determined according to the conveying medium of the lined non-metallic composite steel pipe.

[0016] Optionally, the material of the sealing gasket includes: polytetrafluoroethylene sealing gasket, fluororubber.

[0017] The present invention also provides a method for installing a connector device, the method comprising:

[0018] Placing the corrosion-resistant alloy pressure ring in the first groove, and arranging the sealing gasket between the two steel flanges and at the inner edges of the steel flanges;

[0019] Align the two steel flanges respectively connected to the ends of the steel base pipes in the two lined non-metallic composite steel pipes;

[0020] Fasten the two steel flanges by fixing components;

[0021] The two steel flanges are arranged opposite to each other, and first grooves are respectively arranged in the middle of the sealing surfaces of the two steel flanges; the corrosion-resistant alloy pressure ring is arranged in the first groove.

[0022] Technical effects and advantages of the present invention:

[0023] 1. The present invention adopts corrosion-resistant alloy pressure ring and sealing gasket for double sealing, which reduces the risk of joint leakage. 2. An annular groove is processed on the sealing surface of the neck butt-welded flange to facilitate the placement of the corrosion-resistant alloy pressure ring and to compress the inner lining flange of the flange end face. 3. A step is formed on the non-metallic covering layer of the flange sealing surface to facilitate the positioning of the sealing ring. 4. By selecting sealing gaskets and corrosion-resistant alloy pressure rings of different thicknesses and adjusting the gap between the two flanges, different compression ratios of the sealing gasket and the flange material can be achieved to meet the needs of on-site working conditions.

[0024] Other features and advantages of the present invention will be described in the following description, and partly become obvious from the description, or be understood by implementing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a first structural diagram of a lined non-metallic composite steel pipe joint device with a double sealing structure;

[0026] Figure 2 for Figure 1 A partial enlarged view of the grooves and flanged steps in the structure;

[0027] Figure 3 It is a second structural diagram of the lined non-metallic composite steel pipe joint device;

[0028] Figure 4It is the third structural diagram of the lined non-metallic composite steel pipe joint device;

[0029] Description of the drawings: 1-steel base pipe, 2-non-metallic liner pipe, 3-weld, 4-bolt, 5-steel flange, 6-corrosion-resistant alloy pressure ring, 7-sealing gasket, 8-nut, 9-groove, 10-flanged step, 11-clamp. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings provided by the present invention, and the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0032] In order to solve the deficiencies of the prior art, the present invention discloses a lined non-metallic composite steel pipe joint device with a double sealing structure, the joint device comprising: two steel flanges respectively connected to the ends of the steel base pipes in the two lined non-metallic composite steel pipes, a corrosion-resistant alloy pressure ring, a sealing gasket and a fixing component; the two steel flanges are arranged opposite to each other, and a first groove is respectively arranged in the middle of the sealing surface of the two steel flanges; the fixing component fixes the two steel flanges through the bolt holes on the outer edges of the steel flanges; the corrosion-resistant alloy pressure ring is arranged in the first groove; the sealing gasket is arranged between the two steel flanges and located at the inner edge of the steel flange. The device can ensure that the medium in the pipeline does not leak and does not contact the steel base pipe, and can also ensure the connection strength of the joint, which is convenient for on-site installation. At the same time, the overall cost of the lined non-metallic composite pipe joint sealing structure is relatively low to meet the needs of on-site use.

[0033] In order to better understand this solution, the following Figure 1 The lined non-metallic composite steel pipe joint device with double sealing structure is introduced in detail as follows:

[0034] The joint device comprises: two steel flanges 5 respectively connected to the ends of the steel base pipe 1 in the two lined non-metallic composite steel pipes, a corrosion-resistant alloy pressure ring 6, a sealing gasket 7 and a fixing component for fixing the two steel flanges.

[0035] The two steel flanges 5 are arranged opposite to each other, and the first grooves 9 are respectively arranged on the sealing surfaces of the two steel flanges. Specifically, the steel flange 5 is a necked butt-welded flange (the flange size and the number and specifications of the fastening studs can refer to GB / T 9124-2019 "Steel Pipe Flange"), and an annular first groove 9 is machined on its sealing surface. The steel flange 5 is made of the same or similar material as the steel base pipe 1, and is welded to the end of the steel base pipe 1 through the weld 3.

[0036] The non-metallic composite steel pipe with inner lining includes: a steel base pipe 1 and a non-metallic inner lining pipe 2. The non-metallic inner lining pipe 2 has an outer diameter slightly larger than the inner diameter of the steel base pipe 1, and is inserted into the steel base pipe 1 after the steel flange 5 is welded. An interference fit is formed between the lining pipe and the base pipe, and a certain length of the non-metallic inner lining pipe 2 is reserved at the pipe end. It should also be noted that the non-metallic inner lining pipe 2 is a non-metallic pipe made of polyethylene or polypropylene.

[0037] After the steel base pipe 1 and the non-metallic liner pipe 2 are interlaced and compounded, the stress is released, and the non-metallic liner pipe 2 reserved at the pipe end is heated, and the non-metallic liner pipe 2 is flanging processed at the pipe end to form a non-metallic covering layer covering the end face of the steel flange 5. A special mold should be used during the flanging process to press the non-metallic covering layer on the end face of the steel flange 5 to form a second groove and a flanging step 10, such as Figure 2 shown.

[0038] The corrosion-resistant alloy pressure ring 6 is arranged in the second groove. Specifically, the corrosion-resistant alloy pressure ring can be made of stainless steel, nickel-based alloy, copper alloy and other materials according to different internal transmission media; the sealing gasket 7 is arranged at the step of the flange step, and the material of the sealing gasket is polytetrafluoroethylene, fluororubber and the like.

[0039] The fixing components are arranged on the outer edge of the steel flange. Specifically, the fixing components are bolts 4 and nuts 8.

[0040] It should be noted that the non-metallic covering layer can also be processed into a plane, and the end face of the liner flange is used as the sealing surface. That is, in this alternative solution, there is only a corrosion-resistant alloy pressure ring, and the end face of the flange structure is also a sealing surface. Figure 3 The specific principle is: the end faces of the flange structure are pressed against each other, and their contact surface serves as the sealing surface; the pressure ring presses the flange of the liner to achieve sealing.

[0041] It should be noted that the present invention can also design the two steel flanges to be conical, and adopt the clamp 11 to tighten the two flanges by tightening the clamp bolts, such as Figure 4 shown.

[0042] The present invention discloses a lined non-metallic composite steel pipe joint device with a double sealing structure, the joint device comprises: two steel flanges respectively connected to the ends of the steel base pipes in two lined non-metallic composite steel pipes, a corrosion-resistant alloy pressure ring, a sealing gasket and a fixing component; the two steel flanges are arranged opposite to each other, and a first groove is respectively arranged in the middle of the sealing surfaces of the two steel flanges; the fixing component fixes the two steel flanges through the bolt holes on the outer edges of the steel flanges; the corrosion-resistant alloy pressure ring is arranged in the first groove; the sealing gasket is arranged between the two steel flanges and located at the inner edge of the steel flange. The adoption of this structure realizes the double sealing of the lined non-metallic composite steel pipe joint, reduces the risk of leakage on site, and has the advantages of simple operation and quick installation.

[0043] The present invention also provides an installation method for a joint device, the method comprising: placing a corrosion-resistant alloy pressure ring in a first groove, and setting a sealing gasket between two steel flanges and located at the inner edge of the steel flange; aligning two steel flanges respectively connected to the ends of the steel base pipe in two lined non-metallic composite steel pipes; fastening the two steel flanges by a fixing component; wherein the two steel flanges are arranged opposite to each other, and first grooves are respectively set in the middle of the sealing surfaces of the two steel flanges; the corrosion-resistant alloy pressure ring is set in the first groove.

[0044] Since the content protected by this method is similar to that protected by the above-mentioned device, no further introduction will be given here. Please refer to the above-mentioned device explanation section for details.

[0045] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A lined non-metallic composite steel pipe joint device with a double sealing structure, characterized in that: The joint device comprises: two steel flanges respectively connected to the ends of the steel base pipes in the two lined non-metallic composite steel pipes, a corrosion-resistant alloy pressure ring, a sealing gasket and a fixing component; The two steel flanges are arranged opposite to each other, and a first groove is respectively arranged in the middle of the sealing surfaces of the two steel flanges; the fixing component fixes the two steel flanges through the bolt holes on the outer edges of the steel flanges; the corrosion-resistant alloy pressure ring is arranged in the first groove; the sealing gasket is arranged between the two steel flanges and located at the inner edge of the steel flanges.

2. The lined non-metallic composite steel pipe joint device with a double sealing structure according to claim 1 is characterized in that: The lined non-metallic composite steel pipe also includes: a non-metallic lining pipe inserted into the steel base pipe, and a non-metallic lining pipe of a predetermined length is retained at the pipe end of the lined non-metallic composite steel pipe, and the non-metallic lining pipe with the predetermined length is flanging-processed to form a non-metallic covering layer covering the corresponding steel flange sealing surface.

3. The lined non-metallic composite steel pipe joint device with a double sealing structure according to claim 2 is characterized in that: The second groove and the flange step are formed respectively by pressing the non-metallic covering layer on the sealing surfaces of the two steel flanges; Correspondingly, the corrosion-resistant alloy pressure ring is arranged in the second groove; and the sealing gasket is arranged at the step of the flanging step.

4. The lined non-metallic composite steel pipe joint device with a double sealing structure according to claim 2, characterized in that: The non-metallic liner pipe is a non-metallic pipe made of polyethylene or polypropylene.

5. The lined non-metallic composite steel pipe joint device with a double sealing structure according to claim 2, characterized in that: The joint device also includes a weld for connecting the end of the steel base pipe and the steel flange.

6. The lined non-metallic composite steel pipe joint device with a double sealing structure according to claim 1, characterized in that: The steel flange is a neck butt welding flange.

7. The lined non-metallic composite steel pipe joint device with a double sealing structure according to claim 2, characterized in that: The fixing component comprises a component consisting of a bolt and a nut.

8. The lined non-metallic composite steel pipe joint device with a double sealing structure according to claim 1, characterized in that: The material of the corrosion-resistant alloy pressure ring is determined according to the conveying medium of the lined non-metallic composite steel pipe.

9. The lined non-metallic composite steel pipe joint device with a double sealing structure according to claim 1, characterized in that: The materials of the sealing gasket include: polytetrafluoroethylene sealing gasket and fluororubber.

10. The method for installing a joint device according to any one of claims 1 to 9, characterized in that: The method comprises: Placing the corrosion-resistant alloy pressure ring in the first groove, and arranging the sealing gasket between the two steel flanges and at the inner edges of the steel flanges; Align the two steel flanges respectively connected to the ends of the steel base pipes in the two lined non-metallic composite steel pipes; Fasten the two steel flanges by fixing components; The two steel flanges are arranged opposite to each other, and first grooves are respectively arranged in the middle of the sealing surfaces of the two steel flanges; the corrosion-resistant alloy pressure ring is arranged in the first groove.

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