A plastic-coated steel pipe connection device suitable for low-temperature working conditions

Abstract

This utility model discloses a plastic-coated steel pipe docking device suitable for low-temperature working conditions, including a low-temperature steel pipe docking structure comprising flanges, corrugated pipes, limiting screws, elastic connecting strips, limiting ear plates, and plastic-coated connecting steel pipes. One end of the plastic-coated connecting steel pipe is welded to the flange and the corrugated pipe, while the other end is free to move. The outer wall is covered with a 5mm aluminum silicate fiber coating. Limiting ear plates are provided around the two flanges, and limiting screws are inserted into the flared ear holes. The screws are bound together by the elastic connecting strip. During operation, the corrugated pipe is pre-compressed and positioned with the assistance of the limiting structure. After installation, the elastic function is released, and the axial extension of the corrugated pipe and the movement of the free end of the plastic-coated connecting steel pipe absorb the frost heave stress. The coating maintains the surface temperature to prevent embrittlement, thus solving the problem of frost heave damage in traditional rigid connections.

Description

Technical Field

[0001] This utility model relates to the field of steel pipe connection technology, specifically a plastic-coated steel pipe docking device suitable for low-temperature working conditions. Background Technology

[0002] Plastic-coated steel pipe, also known as plastic-coated pipe or steel-plastic composite pipe, is a composite pipe made of steel pipe as the base material. It is formed by fusing a polymer anti-corrosion coating on the inner and outer surfaces of the steel pipe through electrostatic spraying, rotational molding, dip coating or vacuum coating processes. Common connection methods for plastic-coated steel pipe include flange connection, threaded connection, grooved connection and socket connection.

[0003] Currently, mainstream plastic-coated steel pipe connection devices are suitable for normal working environments. However, in extreme working conditions such as low temperature and high altitude, there is still the problem of axial compression damage caused by freezing heave of steel pipes, resulting in poor stability and durability of plastic-coated steel pipes. Therefore, it is necessary to design an elastic pressure-bearing connection device that can withstand axial forces under extreme environments.

[0004] Therefore, this utility model provides a plastic-coated steel pipe docking device suitable for low-temperature working conditions to solve the above problems. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a plastic-coated steel pipe docking device suitable for low-temperature working conditions, thus solving the aforementioned problems.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a plastic-coated steel pipe docking device suitable for low-temperature operating conditions, comprising:

[0007] A low-temperature steel pipe butt joint structure includes a corrugated pipe. A plastic-coated connecting steel pipe is disposed at the center of the corrugated pipe. One end of the plastic-coated connecting steel pipe is welded to a flange and a corrugated pipe at the same end, and the other end of the plastic-coated connecting steel pipe retains the ability to move freely. At least two limiting lugs are integrally disposed on the peripheral sides of both flanges along the axis, and each limiting lug has a flared lug hole that opens from the center outward. A limiting screw is inserted into the interior of each limiting lug.

[0008] Preferably, the low-temperature steel pipe butt structure further includes flanges, with two flanges arranged as a group, and a corrugated pipe coaxially connected between the two flanges by welding to the center through hole.

[0009] Preferably, a 5mm clearance is maintained between the inner wall of the corrugated pipe and the outer wall of the plastic-coated connecting steel pipe.

[0010] Preferably, the outer wall surface of the plastic-coated connecting steel pipe is uniformly coated with a 5mm thick aluminum silicate fiber coating, and bonded to the steel pipe surface by a high-temperature adhesive.

[0011] Preferably, the open ends of the flared ear holes are all rounded.

[0012] Preferably, the limiting screw, in conjunction with the nut, adjusts the spacing between the limiting lugs.

[0013] Preferably, all the limiting screws are connected and bound together by elastic connecting strips with telescopic capability, and are quickly inserted and elastically pulled into the limiting ear plate for positioning with the flared ear hole. Beneficial effects

[0014] This utility model provides a plastic-coated steel pipe connection device suitable for low-temperature working conditions. Compared with the prior art, it has the following advantages:

[0015] (1) The plastic-coated steel pipe docking device applicable to low temperature working conditions, through the elastic structure design of the corrugated pipe and the plastic-coated connecting steel pipe, enables the device to release the pre-compression through the axial extension of the corrugated pipe in low temperature environment. Combined with the axial movement capability of the free end of the plastic-coated connecting steel pipe, it effectively absorbs the axial stress generated by the freezing heave of the steel pipe, avoids stress concentration caused by rigid constraints, and solves the problem of freezing heave damage of traditional rigid connections. At the same time, by coating the outer wall of the plastic-coated connecting steel pipe with aluminum silicate fiber coating, a low temperature barrier layer can be formed to maintain the surface temperature above -10℃, reduce the risk of low temperature embrittlement of the coating, and improve the stability and durability of the device under low temperature working conditions.

[0016] (2) The plastic-coated steel pipe docking device applicable to low temperature working conditions, through the auxiliary positioning structure of the limiting screw and the elastic connecting strip, and with the flared ear hole, can quickly insert and elastically pull the positioning in the limiting ear plate, lock the relative position of the flange and the bellows before installation, prevent the bellows from deforming during installation, and after the connection is completed, the elastic connecting strip drives the limiting screw to maintain the integrity and quickly remove it, which makes the disassembly and assembly of the device easier. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural perspective view of this utility model;

[0018] Figure 2 This is a three-dimensional radial cross-sectional view of the structure of this utility model;

[0019] Figure 3 This is an equidistant front view of the disassembled structure of this utility model from the outside to the inside;

[0020] Figure 4 This is the utility model Figure 1 Enlarged view of point A in the middle.

[0021] In the figure: 1. Low-temperature steel pipe butt structure; 11. Flange; 12. Corrugated pipe; 13. Limiting screw; 131. Elastic connecting strip; 14. Limiting ear plate; 141. Flared ear hole; 15. Plastic-coated connecting steel pipe; 16. Aluminum silicate fiber coating. Detailed Implementation

[0022] 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.

[0023] Please see Figures 1-4 A plastic-coated steel pipe docking device suitable for low-temperature operating conditions, comprising:

[0024] Low-temperature steel pipe butt structure 1 is a composite pipe formed by fusing a polymer anti-corrosion coating onto the inner and outer surfaces of a steel pipe as the base material through electrostatic spraying, rotational molding, dip coating or vacuum coating processes.

[0025] The low-temperature steel pipe butt structure 1 includes flanges 11, with two flanges 11 arranged as a group. A bellows 12 is coaxially connected between the two flanges 11 via a centrally aligned through-hole by welding. The two flanges 11 are bolted to the main pipe. The bellows 12 is made of 304 stainless steel with a wall thickness of 1.5mm and an axial stiffness designed to be 50N / mm, capable of absorbing a maximum displacement of 30mm. A plastic-coated connecting steel pipe 15 is positioned at the center of the bellows 12, with a 5mm clearance between the inner wall of the bellows 12 and the outer wall of the plastic-coated connecting steel pipe 15. The outer surface of the plastic-coated connecting steel pipe 15 is uniformly coated with a 5mm thick aluminum silicate fiber coating 16, which is bonded to the steel pipe surface using a high-temperature adhesive. One end of the plastic-coated connecting steel pipe 15 is welded to the flange 11 at the same end, while the other end of the plastic-coated connecting steel pipe 15 retains free movement. Each flange 11 has at least two locating lugs 14 integrally formed along its axis on its circumferential side. The locating lugs 14 on the circumferential side of the two flanges 11 must be on the same straight line. Each locating lug 14 has a flared lug hole 141 opening outward from the center. The open end of the flared lug hole 141 is rounded. Each locating lug 14 has a locating screw 13 inserted inside. The locating screw 13, together with a nut, adjusts the spacing between the locating lugs 14, thereby achieving the effect of axial constraint on the locating screw 13 and preventing the locating screw 13 from sliding along the flared lug hole 141 inside the locating lug 14. All locating screws 13 are connected and bound together by an elastic connecting strip 131 with telescopic capability. The elastic connecting strip 131, together with the flared lug hole 141, allows for quick insertion and elastic pulling positioning within the locating lug 14, thereby locking the relative position of the flange 11 and the bellows 12 before installation to prevent deformation.

[0026] During operation, first, based on the low-temperature environment of the plastic-coated steel pipe, pre-compress the corrugated pipe 12 using special tooling (e.g., compress 15mm at -35℃, leaving 10mm for safe expansion); manually stretch the elastic connecting strip 131 to slide the limiting screw 13 into the flared lug 141, adjust the nut to lock the flange 11 spacing, and the elastic connecting strip 131 and the flared lug 141 cooperate to mutually restrain the limiting screw 13, assisting in positioning and preventing the corrugated pipe 12 from deforming during installation. Then, use bolts to connect the flange 11 to the main pipe flange. After connection, manually pull the elastic connecting strip 131 to allow the limiting screw 13 to slide out from the limiting lug 14 through the flared lug 141, thus completing the elastic connection. The 131-driven limit screw 13 prevents loss, and the corrugated pipe 12 releases its elastic function. When the steel pipe freezes and generates axial stress at low temperatures, the corrugated pipe 12 extends axially to release 15mm of pre-compression. The stress energy is consumed through the elastic deformation of the waveform structure. The free end of the plastic-coated steel pipe 15 is allowed to move axially by 10mm to avoid stress concentration. Its outer wall has a 5mm thick aluminum silicate fiber coating 16 that is bonded to the steel pipe with a high-temperature adhesive to form a low-temperature barrier layer, maintaining the surface temperature above -10℃ and reducing the risk of low-temperature embrittlement of the coating. Finally, through the synergy of the corrugated pipe 12 and the free end structure, the axial stress is elastically absorbed, solving the problem of freeze-thaw damage in traditional rigid connections.

[0027] In summary, the elastic structural design of the corrugated pipe 12 and the plastic-coated connecting steel pipe 15 allows the device to release pre-compression through the axial extension of the corrugated pipe 12 in low-temperature environments. Combined with the axial movement capability of the free end of the plastic-coated connecting steel pipe 15, it effectively absorbs the axial stress generated by the freezing heave of the steel pipe, avoiding stress concentration caused by rigid constraints and solving the freezing heave damage problem of traditional rigid connections. Simultaneously, by coating the outer wall of the plastic-coated connecting steel pipe 15 with an aluminum silicate fiber coating 16, a low-temperature barrier layer can be formed, maintaining the surface temperature at - At temperatures above 10℃, the risk of low-temperature embrittlement of the coating is reduced, and the stability and durability of the device under low-temperature conditions are improved. With the auxiliary positioning structure of the limiting screw 13 and the elastic connecting band 131, and in conjunction with the flared ear hole 141, the device can be quickly inserted and elastically pulled into the limiting ear plate 14 for positioning. Before installation, the relative positions of the flange 11 and the bellows 12 are locked to prevent the bellows 12 from deforming during installation. At the same time, after the connection is completed, the elastic connecting band 131 drives the limiting screw 13 to maintain the integrity of the device and quickly remove it, which makes the disassembly and assembly of the device easier.

[0028] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0029] Working Principle: During operation, firstly, based on the low-temperature working environment of the plastic-coated steel pipe, the corrugated pipe 12 is pre-compressed using a special tool (the compression amount is calculated according to the actual working conditions, for example, 15mm compression at -35℃, with a 10mm safety expansion allowance). Then, the elastic connecting strip 131 is manually stretched, and the limiting screws 13 are slid into the flared lugs 141 one by one. By adjusting the nuts, the limiting screws 13 are used to lock the spacing of the flanges 11. At this time, the stretched elastic connecting strip 131 will cooperate with the flared lugs 141 to make the limiting screws 13 mutually restrain each other, achieving the effect of auxiliary positioning and preventing the corrugated pipe 12 from deforming during installation. Then, the flanges 11 can be connected to the main pipe flange using bolts. After the connection is completed, the elastic connecting strip 131 can be manually pulled again, and the limiting screws 13 can be moved one by one from the limiting lugs 14 through the flared lugs 141. The corrugated pipe 12 slides out and detaches, while the elastic connecting band 131 drives the limiting screw 13 to maintain the integrity of the whole to prevent loss. At this time, the corrugated pipe 12 releases its elastic function. When the steel pipe freezes and generates axial stress in a low-temperature environment, the corrugated pipe 12 extends axially and releases the 15mm pre-compression. At the same time, the stress energy is consumed by the elastic deformation of the waveform structure. The free end of the plastic-coated connecting steel pipe 15 is allowed to move axially by 10mm to avoid stress concentration caused by rigid constraints. The stress energy is consumed by the elastic deformation of the waveform structure. At the same time, the 5mm thick aluminum silicate fiber coating 16 on the outer wall of the plastic-coated connecting steel pipe 15 is bonded to the steel pipe by a high-temperature adhesive to form a low-temperature barrier layer, which keeps the surface temperature above -10℃ and reduces the risk of low-temperature embrittlement of the coating. Finally, through the synergistic effect of the corrugated pipe 12 and the free end structure, the elastic absorption of axial stress is achieved, solving the problem of freeze-thaw damage of traditional rigid connections.

[0030] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0031] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A plastic-coated steel pipe docking device suitable for low-temperature operating conditions, comprising: A low-temperature steel pipe butt structure (1) includes a corrugated pipe (12), and a plastic-coated connecting steel pipe (15) is provided at the center of the corrugated pipe (12). The characteristic is that one end of the plastic-coated connecting steel pipe (15) is connected to the flange (11) and the corrugated pipe (12) at the same end by welding, and the other end of the plastic-coated connecting steel pipe (15) retains the ability to move freely. At least two limiting ear plates (14) are integrally provided on the periphery of the two flanges (11) along the axis, and each limiting ear plate (14) is provided with a flared ear hole (141) from the center to the outside. Each limiting ear plate (14) is fitted with a limiting screw (13).

2. The plastic-coated steel pipe docking device suitable for low-temperature working conditions according to claim 1, characterized in that: The low-temperature steel pipe butt structure (1) also includes a flange (11). Two flanges (11) are set as a group, and a corrugated pipe (12) is coaxially connected between the two flanges (11) with the through hole facing the center in the form of welding.

3. The plastic-coated steel pipe docking device suitable for low-temperature working conditions according to claim 1, characterized in that: A 5mm gap is maintained between the inner wall of the corrugated pipe (12) and the outer wall of the plastic-coated connecting steel pipe (15).

4. The plastic-coated steel pipe docking device suitable for low-temperature working conditions according to claim 1, characterized in that: The outer wall surface of the plastic-coated connecting steel pipe (15) is uniformly coated with a 5mm thick aluminum silicate fiber coating (16), and is bonded to the steel pipe surface by a high-temperature adhesive.

5. A plastic-coated steel pipe docking device suitable for low-temperature working conditions according to claim 1, characterized in that: The open ends of the flared ear holes (141) are all rounded.

6. A plastic-coated steel pipe docking device suitable for low-temperature working conditions according to claim 1, characterized in that: The limiting screw (13) is used in conjunction with the nut to adjust the spacing between the locking clips inserted into the limiting ear plate (14).

7. A plastic-coated steel pipe docking device suitable for low-temperature working conditions according to claim 1, characterized in that: All the limiting screws (13) are connected and bound together by elastic connecting strips (131) with telescopic capability, and are quickly inserted and elastically pulled into the limiting ear plate (14) with the flared ear hole (141).

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