Piping systems and methods for installing piping systems

Abstract

This invention provides a piping system and a method for installing the piping system that allow for the smooth insertion of new piping into existing piping. [Solution] The piping system 100 comprises a first insertion sheath pipe 20 that is inserted into an existing pipe 10, and a first new pipe 30 that is inserted into the first insertion sheath pipe 20 and through which fluid flows.

Description

Technical Field

[0001] The present disclosure relates to a piping system and a method for constructing a piping system.

Background Art

[0002] Conventionally, a new pipe has been laid inside an existing pipe. Patent Document 1 discloses an existing pipe, a new pipe inserted into the existing pipe, and a small-diameter pipe inserted into the new pipe.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, there is room for improvement in smoothly inserting a new pipe into an existing pipe.

[0005] An object of the present disclosure is to provide a piping system and a method for constructing a piping system that can smoothly insert a new pipe into an existing pipe.

Means for Solving the Problems

[0006] A piping system according to one aspect of the present disclosure includes a first insertion sheath inserted into an existing pipe, and a first new pipe inserted into the first insertion sheath and through which a fluid flows inside.

Effects of the Invention

[0007] According to the present disclosure, a new pipe can be smoothly inserted into an existing pipe.

Brief Description of the Drawings

[0008] [Figure 1] This is a schematic diagram illustrating a piping system according to the first embodiment of this disclosure. [Figure 2] This is a partial longitudinal cross-sectional view showing a part of the piping system according to the first embodiment of this disclosure. [Figure 3] This is a partial longitudinal cross-sectional view showing a part of the piping system according to the second embodiment of this disclosure. [Figure 4A] This is a partial cross-sectional view illustrating a method for constructing a piping system according to a second embodiment of this disclosure. [Figure 4B] This is a partial cross-sectional view illustrating a method for constructing a piping system according to a second embodiment of this disclosure. [Figure 5] This is a flowchart showing a method for constructing a piping system according to the second embodiment of this disclosure. [Figure 6] This flowchart shows a modified example of the installation method for a piping system according to the first embodiment of this disclosure. [Modes for carrying out the invention]

[0009] As existing pipelines for oil, gas, water, etc., deteriorate, a method known as the pipe-in-pipe method is used to replace aging pipelines by installing new pipelines inside the existing ones. For example, the pipe-in-pipe method is used to replace existing pipelines installed on the seabed. However, the existing pipelines do not necessarily have to be located on the seabed; for example, they may be located on land or underground.

[0010] <First Embodiment> (Piping system) Replacing aging existing pipes is done by installing smaller diameter pipes inside the existing pipes. The piping system 100 according to this embodiment will be described with reference to Figures 1 and 2. In this embodiment, the piping system 100 is installed on the seabed G. The piping system 100 is used, for example, for the transportation of oil and gas. Figure 1 is a schematic diagram illustrating the piping system 100 according to this embodiment. Figure 2 is a partial longitudinal cross-sectional view showing a part of the piping system 100 according to this embodiment. In Figure 2, the existing piping 10 and the first insertion sheath pipe 20 are shown in cross-section.

[0011] The existing piping 10 is, for example, a subsea pipeline used in oil storage bases or offshore oil and gas receiving facilities. The existing piping 10 is, for example, a pipeline for transporting oil from oil tankers anchored in sea berths to onshore refineries and tanks. The existing piping 10 is installed on the seabed G and needs to be replaced with new piping due to corrosion or other reasons. The cross-section of the existing piping 10 is, for example, a long circular pipe. The cross-section of the existing piping 10 is not limited to a circular shape; it is sufficient to have a space inside into which new piping (for example, the first insertion sheath pipe 20 described later) can be inserted. The material of the existing piping 10 is, for example, SS400. The existing piping 10 may be, for example, made of stainless steel, for example, made of steel, or for example, made of metal. The length of the existing piping 10 is, for example, 500m to 5000m. The outer diameter of the existing piping 10 is, for example, 500A. As shown in Figure 1, one end of the existing piping 10 is located, for example, on the seabed G and connected to land-based piping (not shown) that leads to an onshore refinery or tank. The other end of the existing piping 10 is located, for example, on the seabed G and connected to an oil tanker via, for example, a pipe (not shown).

[0012] As shown in Figure 2, the piping system 100 comprises a first insertion sheath pipe 20 and a first newly installed pipe 30. The first insertion sheath pipe 20 is inserted into the existing piping 10. The outer diameter of the first insertion sheath pipe 20 is smaller than the inner diameter of the existing piping 10. The first insertion sheath pipe 20 is a pipe with an outer diameter that allows it to be inserted inside the existing piping 10. The cross-section of the first insertion sheath pipe 20 is, for example, a long, circular pipe. The cross-section of the first insertion sheath pipe 20 is not limited to a circular shape; it is sufficient that it has a space inside into which the first new piping 30, described later, can be inserted. The material of the first insertion sheath pipe 20 is, for example, carbon steel. The length of the first insertion sheath pipe 20 is, for example, 12m to 120m. The outer diameter of the first insertion sheath pipe 20 is, for example, 400A.

[0013] The first newly installed pipe 30 is inserted into the first insertion sheath pipe 20. The outer diameter of the first newly installed pipe 30 is smaller than the inner diameter of the first insertion sheath pipe 20. The first newly installed pipe 30 is a pipe with an outer diameter that allows it to be inserted inside the first insertion sheath pipe 20. The cross-section of the first newly installed pipe 30 is, for example, a long circular pipe. The cross-section of the first newly installed pipe 30 is not limited to a circular shape. Fluids such as gas or oil flow inside the first newly installed pipe 30. The material of the first newly installed pipe 30 is, for example, carbon steel. The length of the first newly installed pipe 30 is, for example, 12m to 120m. The outer diameter of the first newly installed pipe 30 is, for example, 300A.

[0014] In this manner, the first insertion sheath pipe 20 and the first new pipe 30 are arranged inside the existing pipe 10, from the outside in. When viewed from the longitudinal direction of the existing pipe 10, the first space R1 between the existing pipe 10 and the first insertion sheath pipe 20 is filled with seawater. The second space R2 between the first insertion sheath pipe 20 and the first new pipe 30 is filled with a gas such as air during construction.

[0015] Multiple spacers 4 may be provided at predetermined intervals along the longitudinal direction of the first newly installed pipe 30 on the outer circumferential surface of the first newly installed pipe 30. The outer diameter of the spacers 4 is larger than the outer diameter of the first newly installed pipe 30, as shown in Figure 2. The spacers 4 may be provided to cover the entire circumference of the first newly installed pipe 30 in the circumferential direction, or to cover only a part of the circumferential direction. For example, the spacers 4 may be provided at intervals of 5m to 6m along the longitudinal direction of the first newly installed pipe 30. The outer circumferential surface of the first newly installed pipe 30 may be painted. The paint may be, for example, a functional paint. The paint may be, for example, a corrosion-resistant paint. The spacers 4 may be provided, for example, to protect the paint on the outer circumferential surface of the first newly installed pipe 30. In other words, when the first newly installed pipe 30 is placed inside the first insertion sheath pipe 20, the spacer 4 can prevent the paint on the outer surface of the first newly installed pipe 30 from coming into contact with the inner surface of the first insertion sheath pipe 20. When the piping system 100 does not include the first insertion sheath tube 20, when the first newly installed pipe 30 is inserted into the existing pipe 10, a plurality of spacers 4 come into contact with the inner peripheral surface of the existing pipe 10. For example, although the painting on the outer peripheral surface of the first newly installed pipe 30 is easy to protect, it may be difficult to smoothly perform this insertion. Also, for example, there may be a plurality of irregularities 21 (first irregularities described later) on the inner peripheral surface of the existing pipe 10. This is caused by, for example, protruding obstacles on the inner peripheral surface of the existing pipe 10 or a plurality of backstops. The plurality of backstops are provided at predetermined intervals in the longitudinal direction of the existing pipe 10 on the inner peripheral surface of the existing pipe 10. The plurality of backstops are provided, for example, at intervals of 6 m in the longitudinal direction of the existing pipe 10. The presence of a plurality of backstops in the existing pipe 10 may, for example, mean that the existing pipe 10 was manufactured by welding a plurality of pipes using the backstops. When the piping system 100 does not include the first insertion sheath tube 20, when the first newly installed pipe 30 is inserted into the existing pipe 10, a plurality of irregularities (for example, backstops) 21 come into contact with the outer peripheral surface of the first newly installed pipe 30 or the spacers 4, so it may be difficult to smoothly perform this insertion. In addition, in the present embodiment, since the outer peripheral surface of the first insertion sheath tube 20 is unpainted, there is no need to provide the spacer 4 from the viewpoint of protecting the painting. Also, there are no irregularities 21 such as backstops on the inner peripheral surface of the first insertion sheath tube 20, but there may be.

[0016] The piping system 100 according to the present embodiment does not have a configuration in which the first newly installed pipe 30 is directly inserted into the existing pipe 10, but includes the first insertion sheath tube 20 into which the first newly installed pipe 30 is inserted. By inserting the first insertion sheath tube 20 into which the first newly installed pipe 30 is inserted into the existing pipe 10, the frictional resistance between the existing pipe 10 and the first newly installed pipe 30 caused by a plurality of spacers 4 and a plurality of irregularities 21 can be reduced. With such a configuration, the first newly installed pipe 30 can be smoothly inserted into the existing pipe 10.

[0017] In addition, the second space R2 between the first insertion sheath tube 20 and the first newly installed pipe 30 is filled with a gas such as air during insertion. Due to the buoyancy of the filled gas, in the gravitational direction, the force applied to the bottom surface of the existing pipe 10 from the first insertion sheath tube 20 is reduced, and the frictional resistance between the existing pipe 10 and the first insertion sheath tube 20 is reduced. After insertion, the gas such as air may be replaced with a liquid such as seawater for weight adjustment against the risk of floating. Further, the second space R2 reduces the weight during construction, reduces the required construction equipment specifications, reduces the difficulty of construction, and contributes to the reduction of the process labor cost. <0,000,097><0,000,098><0,000,099>The piping system 100 may include a drawing-in member 32. <0,000,100>The drawing-in member 32 includes a ring-shaped member 33 and a cable-like member 34, which will be described later. The drawing-in member 32 is a member for drawing the first newly installed pipe 30 into the existing pipe 10 together with the first insertion sheath tube 20. The drawing-in member 32 is provided at an end in the longitudinal direction of the first newly installed pipe 30 in the direction (second direction X2) in which the first newly installed pipe 30 is inserted into the first insertion sheath tube 20. The drawing-in member 32 is an extension of the first newly installed pipe 30. When the drawing-in member 32 is connected to the first newly installed pipe 30, the drawing-in member 32 and the first newly installed pipe 30 are integrated. In the longitudinal direction of the first newly installed pipe 30, the direction opposite to the direction (second direction X2) in which the first newly installed pipe 30 is inserted into the first insertion sheath tube 20 is the first direction X1. In the longitudinal direction of the first newly installed pipe 30, the direction (second direction X2) in which the first newly installed pipe 30 is inserted into the first insertion sheath tube 20 may be referred to as the front, and the direction (first direction X1) opposite to the direction (second direction X2) in which the first newly installed pipe 30 is inserted into the first insertion sheath tube 20 may be referred to as the rear. <0,000,101>For example, during the process of combining the first newly installed pipe 30 and the first insertion sheath tube 20 on land, the drawing-in member 32 may be drawn into the first insertion sheath tube 20 in the second direction X2 relative to the first insertion sheath tube 20, so that the drawing-in member 32 and the first newly installed pipe 30 are inserted into the first insertion sheath tube 20. The material of the drawing-in member 32 is, for example, a carbon steel material. <0,000,102><0,000,103><0,000,104>A ring-shaped member 33 may be provided at the end of the first newly installed pipe 30 in the second direction X2. A cable-like body 34 is connected to the ring-shaped member 33 for pulling both the first newly installed pipe 30 and the first insertion sheath pipe 20 into the existing pipe 10. The cable-like body 34 is, for example, a pull-in wire or a pull-in rope. The end of the cable-like body 34 opposite to the end connected to the ring-shaped member 33 is connected to, for example, a winch (not shown). The winch is installed, for example, on land or on a ship.

[0020] The piping system 100 according to this embodiment includes a pull-in member 32 for pulling the first new pipe 30 and the first insertion sheath pipe 20 into the existing pipe 10. With this configuration, the first new pipe 30 can be smoothly inserted into the existing pipe 10.

[0021] The piping system 100 may also include a plug member 22. The plug member 22 is provided at the end of the first insertion sheath pipe 20, on the side in the direction (second direction X2) in which the first insertion sheath pipe 20 is inserted into the existing piping 10. The plug member 22 connects the first insertion sheath pipe 20 and the first new piping 30. Since the first insertion sheath pipe 20 and the first new piping 30 are connected by the plug member 22, both the first insertion sheath pipe 20 and the first new piping 30 can be inserted into the existing piping 10 by pulling in at least one of the first insertion sheath pipe 20 or the first new piping 30. The plug member 22 may be provided so as to cover the end of the first insertion sheath pipe 20. It may be provided at the end on the side in the direction (first direction X1) opposite to the direction in which the first insertion sheath pipe 20 is inserted into the existing piping 10. The material of the plug member 22 is, for example, carbon steel.

[0022] The piping system 100 according to this embodiment is provided with a plug member 22 at the end of the first insertion sheath pipe 20 on the side facing the second direction X2. With this configuration, it is possible to easily fill the second space R2 between the outer surface of the first newly installed pipe 30 and the inner surface of the first insertion sheath pipe 20 with a gas such as air when inserting it. Due to the buoyancy of the filled gas, the force applied from the first insertion sheath pipe 20 to the bottom surface of the existing pipe 10 in the direction of gravity is reduced, and the frictional resistance between the existing pipe 10 and the first insertion sheath pipe 20 is reduced. As a result, the first insertion sheath pipe 20 can be smoothly inserted into the existing pipe 10.

[0023] The first newly installed pipe 30 protrudes from the first insertion sheath pipe 20. At the end of the first newly installed pipe 30 on the side of the second direction X2, it protrudes longitudinally from the end of the first insertion sheath pipe 20. The plug member 22 is through which the portion of the first newly installed pipe 30 that protrudes from the first insertion sheath pipe 20 (forward protruding portion 35) is inserted. The plug member 22 has a through hole 23 through which the first newly installed pipe 30 is inserted. The plug member 22 is annular in shape. The forward protruding portion 35 of the first newly installed pipe 30 passes through the through hole 23 of the plug member 22. The through hole 23 only needs to be structured such that the first newly installed pipe 30 is inserted through it and air or the like that is filled into the second space R2 during insertion does not leak out. The inner circumferential surface of the through hole 23 and the outer circumferential surface of the first newly installed pipe 30 should be in close contact.

[0024] In the piping system 100 according to this embodiment, the first newly installed pipe 30, which has an outer diameter smaller than the inner diameter of the first insertion sheath pipe 20, protrudes from the first insertion sheath pipe 20, so that the first newly installed pipe 30 and the first insertion sheath pipe 20 can be easily pulled in and inserted into the existing piping 10. Furthermore, even when the first newly installed pipe 30 protrudes from the first insertion sheath pipe 20 in this manner, the plug member 22 is used, so that the second space R2 between the outer surface of the first newly installed pipe 30 and the inner surface of the first insertion sheath pipe 20 can be easily filled with a gas such as air during insertion. As a result, the first insertion sheath pipe 20 can be smoothly inserted into the existing piping 10.

[0025] The piping system 100 includes rib members 24. However, the rib members 24 are optional. The rib member 24 is connected to the plug member 22 and to the portion of the first newly installed piping 30 that protrudes from the first insertion sheath pipe 20 (forward protruding portion 35). The rib member 24 is a flat plate member. In plan view, the rib member 24 is, for example, triangular (a right-angled triangle in the illustrated example). The rib member 24 is not limited to a triangular shape in plan view; for example, it may be trapezoidal. The rib member 24 may also be frustoconical. The material of the rib member 24 is, for example, carbon steel. The rib member 24 is positioned to incline in the second direction X2 when viewed from above the first newly installed pipe 30 (for example, as indicated by the arrow in Figure 2, i.e., as viewed from the direction perpendicular to the longitudinal direction of the first newly installed pipe 30). That is, the rib member 24 has an inclined portion (corresponding to the hypotenuse in the case of a triangle) that inclines towards the first newly installed pipe 30 as it moves toward the second direction X2 when viewed from above the first newly installed pipe 30. Multiple rib members 24 are arranged on the outer surface of the first newly installed pipe 30 at intervals in the circumferential direction. Preferably, the rib members 24 are arranged on the outer surface of the first newly installed pipe 30 at equal intervals in the circumferential direction. For example, it is preferable that 4 to 12 rib members 24 are arranged on the outer surface of the first newly installed pipe 30 at equal intervals in the circumferential direction. When 4 rib members 24 are arranged on the outer surface of the first newly installed pipe 30, it is preferable that the rib members 24 are arranged at 90° intervals when viewed from the longitudinal direction of the first newly installed pipe 30. When 12 rib members 24 are arranged on the outer surface of the first newly installed pipe 30, it is preferable that the rib members 24 are arranged at 30° intervals when viewed from the longitudinal direction of the first newly installed pipe 30. Multiple rib members 24 are formed in a conical shape on the outer surface of the first newly installed pipe 30. The outer diameter of the conical portion decreases as it moves in the direction of insertion into the existing pipe 10 (second direction X2). In other words, the conical portion is inclined to move closer to the first newly installed pipe 30 as it moves in the second direction X2.

[0026] In the piping system 100 according to this embodiment, the outer diameter of the conical portion formed by the plurality of rib members 24 decreases as the first newly installed pipe 30 and the first insertion sheath pipe 20 are inserted into the existing pipe 10. The plurality of rib members 24 function as guide members when pulling the first newly installed pipe 30 and the first insertion sheath pipe 20 into the existing pipe 10. This allows the first insertion sheath pipe 20 to be smoothly inserted into the existing pipe 10. Furthermore, the multiple rib members 24 also have the function of smoothly transmitting the force exerted on the first newly installed pipe 30 to the first insertion sheath pipe 20. In addition, when the first newly installed pipe 30 is pushed in the second direction X2 relative to the existing pipe 10, the multiple rib members 24 also have the function of smoothly transmitting the force used to push the first newly installed pipe 30 to the first insertion sheath pipe 20.

[0027] By the way, with the first newly installed pipe 30 inserted into the first insertion sheath pipe 20, instead of pulling either the first newly installed pipe 30 or the first insertion sheath pipe 20 in a second direction X2 relative to the existing pipe 10, or in combination with pulling either the first newly installed pipe 30 or the first insertion sheath pipe 20 in a second direction X2 relative to the existing pipe 10, the first newly installed pipe 30 and the first insertion sheath pipe 20 may be inserted into the existing pipe 10 by pushing either the first newly installed pipe 30 or the first insertion sheath pipe 20 in a second direction X2 relative to the existing pipe 10. Alternatively, with the first newly installed pipe 30 inserted into the first insertion sheath pipe 20, both the first newly installed pipe 30 and the first insertion sheath pipe 20 may be pushed in a second direction X2 relative to the existing pipe 10. In this case, the piping system 100 includes a pushing member 40. The pushing member 40 pushes in the first new pipe 30. The first new pipe 30 is inserted into the existing pipe 10 together with the first insertion sheath pipe 20 by being pushed in by the pushing member 40. The pushing member 40 only needs to have a mechanism for pushing the first new pipe 30 into the existing pipe 10. For example, as shown in Figure 2, the pushing member 40 is a drive mechanism consisting of a first clamp 41 that grips the outer surface of the first new pipe 30 and a jack 42 that connects the first clamp 41 and a second clamp 43 that grips the outer surface of the existing pipe 10. The jack 42, connected to the first clamp 41 provided at the end of the existing pipe 10 in the first direction X1, pushes the first new pipe 30 into the existing pipe 10 in the second direction X2 together with the first insertion sheath pipe 20. Another example of the pushing member 40 is a mechanism in which the pushing member 40 is placed inside the first insertion sheath tube 20, that is, the pushing member 40 grips the first insertion sheath tube 20 from the inside. The first new pipe 30 is pushed into the first insertion sheath tube 20 by the pushing member 40 placed inside the first insertion sheath tube 20, and is inserted into the existing pipe 10 together with the first insertion sheath tube 20.

[0028] The piping system 100 according to this embodiment includes a pushing member 40 for pushing the first newly installed pipe 30 into the existing pipe 10. With this configuration, the first newly installed pipe 30 and the first insertion sheath pipe 20 can be smoothly inserted into the existing pipe 10. In this embodiment, both a pull-in member 32 and a pushing member 40 are provided, but only one of the pull-in member 32 and the pushing member 40 may be provided, or both the pull-in member 32 and the pushing member 40 may be omitted. If both the pull-in member 32 and the pushing member 40 are omitted, the first newly installed pipe 30 and the first insertion sheath pipe 20 may be inserted into the existing pipe 10 by a pushing mechanism installed on land L.

[0029] The pushing member 40 may push the first insertion sheath pipe 20 into the existing pipe 10 together with the first newly installed pipe 30. In this case, the pushing member 40 only needs to have a mechanism for pushing the first insertion sheath pipe 20 into the existing pipe 10. For example, the first clamp 41 grips the outer surface of the first insertion sheath pipe 20. The pushing member 40 is a drive mechanism consisting of the first clamp 41 and a jack 42 that connects the first clamp 41 and the second clamp 43 that grips the outer surface of the existing pipe 10. The jack 42, connected to the first clamp 41 provided at the end of the existing pipe 10 in the first direction X1, pushes the first insertion sheath pipe 20 into the existing pipe 10 in the second direction X2 together with the first newly installed pipe 30. Furthermore, if the pushing member 40 is a mechanism that grips the first newly installed pipe 30 from the inside, the first insertion sheath pipe 20 is pushed in by the pushing member 40 which is positioned inside the first newly installed pipe 30.

[0030] The piping system 100 according to this embodiment includes a pushing member 40 for pushing the first insertion sheath pipe 20 into the existing piping 10. With this configuration, the first insertion sheath pipe 20 and the first new piping 30 can be smoothly inserted into the existing piping 10.

[0031] There may be multiple irregularities (first irregularities) 21 on the inner surface of the existing pipe 10, and multiple irregularities (second irregularities) 31 on the outer surface of the first new pipe 30. The first irregularities 21 are caused, for example, by protruding obstacles on the inner surface of the existing pipe 10 or by multiple backing plates. The second irregularities 31 are, for example, multiple spacers 4 provided at predetermined intervals along the longitudinal direction of the first new pipe 30.

[0032] The piping system 100 according to this embodiment includes a first insertion sheath pipe 20 into which the first new pipe 30 is inserted. If the piping system 100 does not include the first insertion sheath pipe 20, when the first new pipe 30 is inserted into the existing pipe 10, a plurality of second protrusions 31 will come into contact with the inner surface of the existing pipe 10, and a plurality of first protrusions (backing plates) 21 will come into contact with the outer surface of the first new pipe 30 or the second protrusions 31. By inserting the first insertion sheath pipe 20 into which the first new pipe 30 is inserted into the existing pipe 10, the frictional resistance between the existing pipe 10 and the first new pipe 30 caused by the plurality of first protrusions 21 and the plurality of second protrusions 31 can be reduced. With this configuration, the first new pipe 30 can be smoothly inserted into the existing pipe 10.

[0033] <Second Embodiment> In the first embodiment, the piping system 100 is exemplified as comprising one first insertion sheath pipe 20 as an insertion sheath pipe and one first new pipe 30 as a new pipe. However, the insertion sheath pipe and the new pipe are not limited to one each. Multiple insertion sheath pipes and new pipes may be provided. For example, in the second embodiment, as shown in Figure 3, the piping system 200 is configured to include two insertion sheath pipes (first insertion sheath pipe 20, second insertion sheath pipe 20A) and two new piping pipes (first new piping pipe 30, second new piping pipe 30A). Note that the number of insertion sheath pipes and new piping pipes is not limited to two each. Referring to Figure 3, the piping system 200 according to the second embodiment will be described. The same reference numerals are used for parts identical to those in the first embodiment, and their descriptions are omitted. The differences will be described primarily.

[0034] Figure 3 is a schematic diagram illustrating the piping system 200 according to this embodiment. Figure 3 is a partial longitudinal cross-sectional view showing a part of the piping system 200 according to this embodiment. In Figure 3, the existing piping 10 and the first insertion sheath pipe 20 and the second insertion sheath pipe 20A are shown in cross-section. The piping system 200 comprises a first insertion sheath pipe 20, a first new pipe 30, a second insertion sheath pipe 20A, and a second new pipe 30A.

[0035] The second insertion sheath pipe 20A is inserted into the existing piping 10. The second insertion sheath pipe 20A has the same configuration as the first insertion sheath pipe 20. That is, the outer diameter of the second insertion sheath pipe 20A is smaller than the inner diameter of the existing piping 10. The second insertion sheath pipe 20A is a pipe with an outer diameter that can be inserted inside the existing piping 10. The cross-section of the second insertion sheath pipe 20A is, for example, a long circular pipe. The cross-section of the second insertion sheath pipe 20A is not limited to a circular shape; it is sufficient that it has a space inside into which the second new piping 30A, described later, can be inserted. The material of the second insertion sheath pipe 20A is, for example, carbon steel. The length of the second insertion sheath pipe 20A is, for example, 12m to 120m. The outer diameter of the second insertion sheath pipe 20A is, for example, 400A.

[0036] The second newly installed pipe 30A is inserted into the second insertion sheath pipe 20A. The second newly installed pipe 30A has the same configuration as the first newly installed pipe 30. That is, the outer diameter of the second newly installed pipe 30A is smaller than the inner diameter of the second insertion sheath pipe 20A. The second newly installed pipe 30A is a pipe with an outer diameter that can be inserted inside the second insertion sheath pipe 20A. The cross-section of the second newly installed pipe 30A is, for example, a long circular pipe. The cross-section of the second newly installed pipe 30A is not limited to a circular shape. Fluids such as gas or oil flow inside the second newly installed pipe 30A. The material of the second newly installed pipe 30A is, for example, carbon steel. The length of the second newly installed pipe 30A is, for example, 12m to 120m. The outer diameter of the second newly installed pipe 30A is, for example, 300A.

[0037] The first insertion sheath pipe 20 is located in front of the second insertion sheath pipe 20A. The first insertion sheath pipe 20 and the second insertion sheath pipe 20A are connected. The first new piping 30 is located in front of the second new piping 30A. The first new piping 30 and the second new piping 30A are connected. The method for connecting these pipes will be described later.

[0038] The pushing member 40 pushes in the second new pipe 30A. The second new pipe 30A is inserted into the existing pipe 10 together with the second insertion sheath pipe 20A by being pushed in by the pushing member 40. The pushing member 40 only needs to have a mechanism for pushing the second new pipe 30A into the existing pipe 10. For example, the pushing member 40 may be configured to grip the outer surface of the existing pipe 10 and push the second new pipe 30A into the existing pipe 10 in the second direction X2 together with the second insertion sheath pipe 20A. Alternatively, the pushing member 40 may be a mechanism that grips the second insertion sheath pipe 20A from the inside. The second newly installed pipe 30A is pushed into the pushing member 40 positioned inside the second insertion sheath pipe 20A, and is inserted into the existing pipe 10 together with the second insertion sheath pipe 20A. Furthermore, if the pushing member 40 is a mechanism that grips the second newly installed pipe 30A from the inside, the second insertion sheath pipe 20A is pushed in by the pushing member 40 which is positioned inside the second newly installed pipe 30A. Furthermore, the first insertion sheath pipe 20 and the first newly installed pipe 30 may be joined to the second insertion sheath pipe 20A and the second newly installed pipe 30A while they are inserted into the existing pipe 10, respectively.

[0039] (Installation method for piping systems) Referring to Figures 3 to 5, the construction method S200 of the piping system 200 according to the second embodiment will be explained. Figures 4A and 4B are partial cross-sectional views illustrating the construction method S200 of the piping system 200. In Figures 4A and 4B, the first insertion sheath pipe 20 and the second insertion sheath pipe 20A are shown in cross-section. Figure 5 is a flowchart of the construction method of the piping system 200.

[0040] The construction method S200 for the piping system 200 is as follows: the piping system 200 comprises a first insertion sheath pipe 20, a first new pipe 30, a second insertion sheath pipe 20A, and a second new pipe 30A. The construction method S200 for the piping system 200 comprises a new pipe welding step S1 and an insertion sheath pipe welding step S2. The new pipe welding step S1 is the step of connecting the first new pipe 30 and the second new pipe 30A. Figure 4A shows the state before the first new pipe 30 and the second new pipe 30A are connected. Figure 4B shows the state after the first new pipe 30 and the second new pipe 30A are connected. As shown in Figures 4A and 4B, before the new pipe welding step S1, the first new pipe 30 is placed inside the first insertion sheath pipe 20, and the second new pipe 30A is placed inside the second insertion sheath pipe 20A. At this time, the first end 37 of the first protruding portion 36 of the first new pipe 30 protrudes from the first insertion sheath pipe 20 in the first direction (first direction X1), which is the direction opposite to the direction (second direction X2) in which the first new pipe 30 and the first insertion sheath pipe 20 are inserted into the existing pipe 10. The second end 37A of the second protruding portion 36A of the second new pipe 30A protrudes from the second insertion sheath pipe 20A in the second direction X2, which is the direction in which the second new pipe 30A and the second insertion sheath pipe 20A are inserted into the existing pipe 10. The new pipe welding step S1 is a step of welding the first end 37 of the first protruding portion 36 and the second end 37A of the second protruding portion 36A. In this way, the new pipe welding step S1 welds the first end 37 of the first protruding portion 36 at the rear of the first insertion sheath pipe 20 and the second end 37A of the second protruding portion 36A at the front of the second insertion sheath pipe 20A. A known welding method can be used for welding. In this way, the first new pipe 30 and the second new pipe 30A are connected to form a longer new pipe. If the lengths of the first new pipe 30 and the second new pipe 30A are both 12m, for example, then in the new pipe welding step S1, the first new pipe 30 and the second new pipe 30A are connected to form a 24m long new pipe.

[0041] The insertion sheath tube welding step S2 is a step of connecting the first insertion sheath tube 20 and the second insertion sheath tube 20A. In the insertion sheath tube welding step S2, the first half-pipe 38a and the second half-pipe 38b, which cover the first end 37 of the first protruding portion 36 and the second end 37A of the second protruding portion 36A respectively, are welded to the third end 25 in the first direction X1 of the first insertion sheath tube 20 and the fourth end 25A in the second direction X2 of the second insertion sheath tube 20A. The first half-pipe 38a and the second half-pipe 38b cover a portion of the outer surface of the first protruding portion 36 and a portion of the outer surface of the second protruding portion 36A. For example, in a plan view of the first newly installed pipe 30 and the second newly installed pipe 30A (for example, as shown by the arrow in Figure 4A), the first half-pipe 38a is placed on the upper side and the second half-pipe 38b is placed on the lower side, sandwiching the first protruding portion 36 and the second protruding portion 36A. The first half-pipe 38a and the second half-pipe 38b are placed opposite each other so as to cover the first protruding portion 36 and the second protruding portion 36A. The first split pipe 38a and the second split pipe 38b are welded to the third end 25 in the first direction X1 of the first insertion sheath pipe 20 and to the fourth end 25A in the second direction X2 of the second insertion sheath pipe 20A. A known welding method can be used for welding. In this way, the first insertion sheath tube 20 and the second insertion sheath tube 20A are connected to form an elongated insertion sheath tube. For example, if the lengths of both the first insertion sheath tube 20 and the second insertion sheath tube 20A are 12m, then in the insertion sheath tube welding step S2, the first insertion sheath tube 20 and the second insertion sheath tube 20A become an elongated insertion sheath tube of 24m.

[0042] In this manner, the first new pipe 30 and the second new pipe 30A are connected in the new pipe welding step S1, and the first insertion sheath pipe 20 and the second insertion sheath pipe 20A are connected in the insertion sheath pipe welding step S2. The procedure for construction method S200 is to perform the new pipe welding step S1, followed by the insertion sheath pipe welding step S2. After the new pipe welding step S1 and the insertion sheath pipe welding step S2, the welded insertion sheath pipes (first insertion sheath pipe 20, second insertion sheath pipe 20A) and the welded new pipes (first new pipe 30, second new pipe 30A) are inserted into the existing pipe 10 (existing pipe insertion step).

[0043] The construction method S200 of the piping system 200 according to this embodiment comprises a new pipe welding step S1 and an insertion sheath pipe welding step S2. With this configuration, the new pipes (first new pipe 30 and second new pipe 30A) and the insertion sheath pipes (first insertion sheath pipe 20 and second insertion sheath pipe 20A) can be reliably lengthened. Furthermore, since the welded insertion sheath pipes (20, 20A) and the welded new pipes (30, 30A) are inserted into the existing pipes 10, the risk of damage to the external anti-corrosion coating of the new pipes (30, 30A) during insertion can be reduced. If the insertion sheath pipes (20, 20A) are not used, the new pipes (30, 30A) will move into the existing pipes 10, and if the new pipes (30, 30A) move, for example from 500m to 5000m, the risk of damage due to unexpected wear or detachment of the spacer 4 increases. When using insertion sheath tubes (20, 20A), the distance traveled by the new piping (30, 30A) is limited to, for example, the length of the new piping (30, 30A) and the insertion sheath tubes (20, 20A) (for example, from 12m to 60m), reducing the risk of damage due to wear or detachment of spacer 4.

[0044] (Variations in the installation method of the piping system) Referring to Figure 6, the construction method S100 of the piping system 100 according to the first embodiment will be described. Figure 6 is a flowchart showing a modified example of the construction method S100 of the piping system 100.

[0045] The construction method S100 for the piping system 100 is such that the piping system 100 comprises a first insertion sheath pipe 20, a first new pipe 30, a second insertion sheath pipe 20A, and a second new pipe 30A. The installation method S100 for the piping system 100 comprises a first insertion step S3 and a second insertion step S4. Before the first insertion step S3 and the second insertion step S4, a first insertion sheath pipe 20, which is made longer by joining multiple pipe members (insertion sheath pipes), and a first new pipe 30, which is made longer by joining multiple pipe members (new pipes), are prepared (lengthening step S5). In this case, the first insertion sheath pipe 20 and the first new pipe 30 may each be a single long pipe formed by joining axially adjacent ends of multiple pipe members. For example, if two insertion sheath pipes, each 12m long, are joined together, the first insertion sheath pipe 20 will be lengthened to 24m. For example, if two new pipes, each 12m long, are joined together, the first new pipe 30 will be lengthened to 24m. In this case, any joining method (e.g., welding) can be used to join the ends of the multiple pipe members. The ends of the multiple pipe members may also be joined by directly butting them together. Alternatively, the ends of multiple pipe members may be aligned and then welded. The first insertion step S3 is the step of inserting the first new pipe 30 into the first insertion sheath pipe 20. In the first insertion step S3, the first new pipe 30 is inserted into the first insertion sheath pipe 20 by pulling it in or pushing it relative to the first insertion sheath pipe 20.

[0046] In the second insertion step S4, after the first insertion step S3, the first insertion sheath pipe 20 into which the first new pipe 30 is inserted is inserted into the existing pipe 10. In the second insertion step S4, the first insertion sheath pipe 20 into which the first new pipe 30 is inserted is inserted into the existing pipe 10 by pulling it in or pushing it in relative to the existing pipe 10.

[0047] In the installation method S100 for the piping system 100, a first new pipe 30, which has been lengthened by joining multiple new pipes, is inserted into a first insertion sheath pipe 20, which has been lengthened by joining multiple insertion sheath pipes. This configuration makes it possible to more reliably lengthen both the first new pipe 30 and the first insertion sheath pipe 20.

[0048] The technical scope of this disclosure is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of this disclosure.

[0049] For example, the piping system 100 may be used for water supply. The inner surface of the existing pipe 10 and the outer surface of the first newly installed pipe 30 do not need to have any irregularities. The first newly installed pipe 30 does not have to protrude from the first insertion sheath pipe 20. In this case, a pull-in member 32 may be provided at the end of the first insertion sheath pipe 20 in the longitudinal direction in which the first newly installed pipe 30 is inserted into the first insertion sheath pipe 20 (second direction X2). The pull-in member 32, push-in member 40, plug member 22, and rib member 24 may be omitted.

[0050] Furthermore, it is possible to replace the components in the above embodiments with well-known components as appropriate, without departing from the spirit of this disclosure, and the above-described modifications may be combined as appropriate.

[0051] (Note) The above embodiment can be understood, for example, as follows:

[0052] <1> A piping system according to one aspect of this disclosure includes a first insertion sheath pipe inserted into an existing pipe, and a first new pipe inserted into the first insertion sheath pipe and through which fluid flows. It is characterized by being equipped with [the following features].

[0053] By inserting the first insertion sheath pipe, into which the first new pipe is inserted, into the existing pipe, the frictional resistance between the existing pipe and the first new pipe, caused by multiple spacers and irregularities, can be reduced. With this configuration, the first new pipe can be smoothly inserted into the existing pipe.

[0054] <2> the above <1> The piping system may also be configured to include a pull-in member for pulling the first newly installed pipe into the existing piping, together with the first insertion sheath pipe.

[0055] The pull-in member for pulling the first newly installed pipe and the first insertion sheath pipe into the existing pipe allows the first newly installed pipe to be smoothly inserted into the existing pipe.

[0056] <3> the above <2> The piping system may employ a configuration in which a plug member is provided at the end of the first insertion sheath pipe, on the side in which the first insertion sheath pipe is inserted into the existing piping.

[0057] The plug member allows for easy filling of the second space between the outer surface of the first newly installed pipe and the inner surface of the first insertion sheath pipe with air or other gas during insertion. The buoyancy of the filled gas reduces the force applied from the first insertion sheath pipe to the bottom surface of the existing pipe in the direction of gravity, thereby reducing frictional resistance between the existing pipe and the first insertion sheath pipe. As a result, the first insertion sheath pipe can be smoothly inserted into the existing pipe.

[0058] <4> the above <3> The piping system may employ a configuration in which the first newly installed pipe protrudes from the first insertion sheath pipe, and the plug member is inserted through the portion of the first newly installed pipe that protrudes from the first insertion sheath pipe.

[0059] Since the first newly installed pipe, whose outer diameter is smaller than the inner diameter of the first insertion sheath pipe, protrudes from the first insertion sheath pipe, the first newly installed pipe and the first insertion sheath pipe can be easily pulled into and inserted into the existing pipe. Furthermore, even when the first newly installed pipe protrudes from the first insertion sheath pipe in this manner, a plug member is used, making it possible to easily fill the second space between the outer surface of the first newly installed pipe and the inner surface of the first insertion sheath pipe with air or other gas during insertion. This allows the first insertion sheath pipe to be smoothly inserted into the existing pipe.

[0060] <5> the above <4> The piping system may include a plurality of rib members connected to the plug member and the portion of the first newly installed piping that protrudes from the first insertion sheath pipe, wherein the outer diameter of the conical portion formed by the plurality of rib members decreases as it moves toward the direction of insertion into the existing piping.

[0061] The multiple rib members function as guide members when pulling the first newly installed pipe and the first insertion sheath pipe into the existing pipe. This allows the first insertion sheath pipe to be smoothly inserted into the existing pipe. The multiple rib members also have the function of smoothly transmitting the pulling force of the first newly installed pipe to the first insertion sheath pipe. Furthermore, when pushing the first newly installed pipe in a second direction relative to the existing pipe, the multiple rib members also have the function of smoothly transmitting the pushing force of the first newly installed pipe to the first insertion sheath pipe.

[0062] <6> the above <1> The piping system may employ a configuration in which a plug member is provided at the end of the first insertion sheath pipe, on the side in which the first insertion sheath pipe is inserted into the existing piping.

[0063] The plug member allows for easy filling of the second space between the outer surface of the first newly installed pipe and the inner surface of the first insertion sheath pipe with air or other gas during insertion. The buoyancy of the filled gas reduces the force applied from the first insertion sheath pipe to the bottom surface of the existing pipe in the direction of gravity, thereby reducing frictional resistance between the existing pipe and the first insertion sheath pipe. As a result, the first insertion sheath pipe can be smoothly inserted into the existing pipe.

[0064] <7> the above <6> The piping system may be configured to include a pushing member for pushing the first new pipe into the existing pipe, and the first new pipe may be inserted into the existing pipe together with the first insertion sheath pipe by being pushed into the pushing member.

[0065] The first newly installed pipe and the first insertion sheath pipe can be smoothly inserted into the existing pipe by the pushing member used to push the first newly installed pipe into the existing pipe.

[0066] <8> the above <7> The piping system may employ a configuration in which the pushing member pushes the first insertion sheath pipe into the existing piping together with the first newly installed piping.

[0067] The first insertion sheath pipe and the first new pipe can be smoothly inserted into the existing pipe by a pushing member that pushes the first insertion sheath pipe into the existing pipe.

[0068] <9> the above <1> ~ <8> A piping system according to any one of the embodiments may employ a configuration in which the inner surface of the existing piping has multiple irregularities, and the outer surface of the first newly installed piping has multiple irregularities.

[0069] By inserting the first insertion sheath pipe, into which the first new pipe is inserted, into the existing pipe, the frictional resistance between the existing pipe and the first new pipe, caused by multiple irregularities, can be reduced. With this configuration, the first new pipe can be smoothly inserted into the existing pipe.

[0070] <10> the above <1> ~ <8> A method for constructing a piping system according to any one embodiment of the above, wherein the piping system comprises a second insertion sheath pipe inserted into the existing piping, and a second new piping inserted into the second insertion sheath pipe and through which fluid flows, wherein the first new piping has a first end of a first protruding portion that protrudes from the first insertion sheath pipe in a first direction opposite to the direction in which the first new piping and the first insertion sheath pipe are inserted into the existing piping, and the second new piping and The invention is characterized by comprising: a new pipe welding step of welding the second end of a second protruding portion that protrudes from the second insertion sheath pipe in a second direction, which is the direction in which the second insertion sheath pipe is inserted into the existing piping; and an insertion sheath pipe welding step of welding the first half pipe and the second half pipe, which cover the first end of the first protruding portion and the second end of the second protruding portion, respectively, to the third end of the first insertion sheath pipe in the first direction and the fourth end of the second insertion sheath pipe in the second direction.

[0071] The welding step S1 for the new piping and the welding step S2 for the insertion sheath pipe ensure that the new piping and the insertion sheath pipe are reliably made longer.

[0072] <11> the above <10> The construction method for the piping system may include a configuration comprising: a first insertion step of inserting the first new piping into the first insertion sheath pipe; and a second insertion step, after the first insertion step, of inserting the first insertion sheath pipe into which the first new piping is inserted into the existing piping.

[0073] By inserting a first new pipe, which has been lengthened by joining multiple new pipes, into a first insertion sheath pipe, which has been lengthened by joining multiple insertion sheath pipes, the first new pipe 30 and the first insertion sheath pipe 20 can be lengthened more reliably. [Explanation of symbols]

[0074] 10 Existing piping 20. First insertion tube 20A Second insertion tube 21. First unevenness (backing plate) 22 Plug member 24 Rib members 25 Third end 25A 4th end 30. First newly installed piping 30A Second newly installed piping 31 2nd unevenness 32 Pull-in member 36 1st protruding part 36A 2nd protruding part 37 First end 37A 2nd end 38a 1st half pipe 38b Second half tube 40 Push-in member 100,200 piping systems G Undersea R1 First Space R2 2nd space S1 New pipe welding step S2 Insertion Tube Welding Step S3 First insertion step S4 Second insertion step S5 Lengthening Step S100, S100 construction method

Claims

1. A first insertion sheath pipe to be inserted into the existing piping, A first newly installed pipe is inserted into the first insertion sheath tube and through which fluid flows, A piping system characterized by having the following features.

2. The piping system according to claim 1, characterized in that it includes a pull-in member for pulling the first newly installed piping into the existing piping together with the first insertion sheath pipe.

3. The piping system according to claim 2, characterized in that a plug member is provided at the end of the first insertion sheath tube, on the side in which the first insertion sheath tube is inserted into the existing piping.

4. The first newly installed pipe protrudes from the first insertion sheath pipe. The plug member is inserted through the portion of the first newly installed piping that protrudes from the first insertion sheath pipe. The piping system according to claim 3.

5. The plug member and a plurality of rib members are provided, which are connected to the portion of the first newly installed piping that protrudes from the first insertion sheath pipe. The outer diameter of the conical portion formed by the multiple rib members decreases as it moves in the direction of insertion into the existing pipe. The piping system according to feature 4.

6. The piping system according to claim 1, characterized in that a plug member is provided at the end of the first insertion sheath tube, on the side in which the first insertion sheath tube is inserted into the existing piping.

7. The device includes a pushing member for pushing the first newly installed pipe into the existing pipe, The first newly installed pipe is inserted into the existing pipe together with the first insertion sheath pipe by being pushed into the pushing member. The piping system described in item 6.

8. The piping system according to claim 7, characterized in that the pushing member pushes the first insertion sheath pipe into the existing piping together with the first newly installed piping.

9. The inner surface of the aforementioned existing pipe has multiple irregularities. The outer surface of the first newly installed pipe has multiple irregularities. The piping system according to any one of claims 1 to 8.

10. A method for constructing a piping system according to any one of claims 1 to 8, The aforementioned piping system is A second insertion sheath pipe is inserted into the aforementioned existing piping, A second newly installed pipe is inserted into the second insertion sheath tube and through which fluid flows, Equipped with, A new piping welding step comprising welding the first end of a first protruding portion of the first new piping, which protrudes from the first insertion sheath pipe in a first direction opposite to the direction in which the first new piping and the first insertion sheath pipe are inserted into the existing piping, and the second end of a second protruding portion of the second new piping, which protrudes from the second insertion sheath pipe in a second direction, which is the direction in which the second new piping and the second insertion sheath pipe are inserted into the existing piping, An insertion sheath tube welding step is performed, in which the first half-pipe and the second half-pipe, which cover the first end of the first protruding portion and the second end of the second protruding portion, respectively, are welded to the third end of the first insertion sheath tube in the first direction and the fourth end of the second insertion sheath tube in the second direction, A method for constructing a piping system, characterized by comprising the following features.

11. A first insertion step involves inserting the first newly installed pipe into the first insertion sheath tube, Following the first insertion step, a second insertion step is performed in which the first insertion sheath pipe into which the first newly installed pipe is inserted is inserted into the existing pipe. A method for constructing a piping system according to claim 10, characterized by comprising the above.

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