JP2023155804A - Pipe replacement method and connection tool - Google Patents

Abstract

To provide a pipe replacement method capable of reducing labor for work necessary for replacing pipes, in pipe replacement work of replacing an existing inner pipe inserted into a protective pipe with a new inner pipe.SOLUTION: A pipe replacement method in which an existing flexible inner pipe 22 inserted from one end 26L side of a protection pipe 26 to the other end 26R side is replaced with a new flexible inner pipe 24, comprises: a connection step of connecting the other end 22R of the existing inner pipe 22 and one end 24L of the new inner pipe 24 with a connection tool 30 on the other end 26R side of the protection pipe 26; and an insertion step of inserting the new inner pipe 24 into the protection pipe 26 from the other end 26R side of the protection pipe 26 while pulling out the existing inner pipe 22 from one end 26L side of the protection pipe 26.SELECTED DRAWING: Figure 3

Description

The present invention relates to a pipe replacement method and a connecting tool.

Patent Document 1 describes a piping renewal method for replacing existing piping covered with a tubular protective material with new piping, in which multiple pipes are cut by cutting the existing piping in the radial direction and the pipe axis direction a step of dividing the existing piping into cut pieces; a pulling out step of pulling out the plurality of cut pieces from the protective material; A piping renewal construction method is disclosed, which includes the step of inserting a new pipe into the inside of the protective material while following the inner circumferential surface of the protective material.

JP 2021-85502 Publication

In the configuration described in Patent Document 1, the new piping is inserted into the protective tube after the step of cutting the existing piping into a plurality of pieces, so it takes time and effort to update the piping. Furthermore, since the existing piping is cut, it takes time and effort to collect the cut existing piping when discarding the existing piping.

An object of the present invention is to provide a piping replacement method that can reduce the labor required for piping replacement in a piping replacement work in which an existing inner pipe inserted into a protection tube is replaced with a new inner pipe. .

The piping replacement method of the first aspect is a piping replacement method in which an existing flexible inner pipe inserted from one end of a protection tube to the other end is replaced with a new flexible inner pipe. a connecting step of connecting the other end of the existing inner pipe and one end of the new inner pipe with a connector on the other end side of the protection tube; The method includes an insertion step of inserting a newly installed inner tube into the protection tube from the other end side of the protection tube.

After connecting the existing inner tube inserted through the protection tube and the new inner tube with a connector, the new inner tube is inserted while pulling out the existing inner tube from one end of the protection tube. As a result, in piping replacement work in which an existing inner pipe inserted into a protection tube is replaced with a new inner pipe, it is easier to replace the existing pipe with a new inner pipe inserted into the protection tube after the process of cutting the existing pipe into multiple pieces. , it is possible to reduce the labor required for replacing piping.

A second aspect of the piping replacement method is the piping replacement method according to the first aspect, in which the insertion step includes applying a lubricant to the outer peripheral surface of the existing inner pipe or the new inner pipe on the other end side of the protection tube. It is done while attaching.

In the insertion process, lubricant is applied to the outer peripheral surface of the existing inner tube or the new inner tube at the other end of the protective tube. Thereby, the frictional resistance between the inner circumferential surface of the protection tube and the outer circumferential surface of the existing inner tube and the outer circumferential surface of the newly installed inner tube can be reduced.

A piping replacement method according to a third aspect is the piping replacement method according to the first aspect, in which the insertion step includes pushing the existing inner pipe or the new inner pipe into the protection pipe at the other end side of the protection pipe. , by pulling out the existing inner pipe from one end side of the protection pipe.

In the insertion process, the existing inner tube is pulled out at one end of the protection tube while pushing in the new inner tube at the other end of the protection tube, so that the existing inner tube and the new inner tube are not pulled excessively inside the protection tube. This prevents it from loosening or loosening excessively. As a result, by keeping the existing inner pipe and the new inner pipe appropriately relaxed inside the protection pipe, and pulling out the existing inner pipe from one end of the protection pipe, the existing inner pipe can be easily loosened when replacing the pipe. Frictional resistance between the outer circumferential surface of the protective tube and the outer circumferential surface of the new inner tube can be reduced.

A piping replacement method according to a fourth aspect is the piping replacement method according to any one of the first to third aspects, wherein the connector includes a central portion and a surface on one side with respect to the axis of the central portion. a first threaded part extending from the inner pipe with a male thread part and screwed into the inner circumferential surface of the new inner pipe at one end of the new inner pipe; and a first threaded part with respect to the axis of the central part. extends from the opposite surface with a reverse male threaded portion formed in a direction opposite to the male threaded portion, and is screwed into the inner circumferential surface of the existing inner pipe at the other end of the existing inner pipe. It has a section and a.

The connector has a first threaded portion and a second threaded portion having a reverse male threaded portion that is a reverse thread than the male threaded portion of the first threaded portion. As a result, the first threaded part can be screwed into the new inner pipe and the second threaded part can be threaded into the existing inner pipe at the same time, improving the workability of connecting the existing inner pipe and the new inner pipe. can be improved.

Further, when the existing inner pipe or the newly installed inner pipe is twisted inside the protective tube, even if either the first threaded part or the second threaded part of the connector becomes loose, the other is tightened. Therefore, compared to the case where a reverse thread is not used, it is possible to prevent the connector from falling off both the existing inner pipe and the new inner pipe inside the protection pipe.

The fifth aspect of the pipe replacement fitting includes a central portion, a male screw portion extending from one surface of the central portion with respect to the axis thereof, and a third screw portion screwed into the inner circumferential surface of one pipe body. a threaded part, and a reverse male threaded part formed in a direction opposite to the male threaded part from a surface opposite to the first threaded part with respect to the axis of the central part; and a second threaded portion that is threaded into the inner circumferential surface of the body.

The connecting tool for pipe replacement has a first threaded portion and a second threaded portion having a reverse male threaded portion that is a reverse thread than the male threaded portion of the first threaded portion. As a result, the first threaded part can be screwed into the new inner pipe and the second threaded part can be threaded into the existing inner pipe at the same time, improving the workability of connecting the existing inner pipe and the new inner pipe. can be improved.

In addition, if one pipe body or the other pipe body is twisted while the first pipe body and the other pipe body are connected, the first threaded part of the connecting tool and the second threaded part Even if one of them loosens, the other will tighten. Therefore, compared to the case where a reverse thread is not used, it is possible to prevent the connector from falling off both the one tube body and the other tube body inside the protection tube.

The connecting tool for replacing pipes according to the sixth aspect is the connecting tool for replacing pipes according to the fifth aspect, and has two mutually parallel two-sided parts on the outer periphery of the central part for hanging tools.

The connecting tool for replacing pipes has two parallel surfaces on the outer periphery of the center portion, on which tools can be hung. Thereby, when screwing the first threaded part and the second threaded part into the existing inner pipe and the newly installed inner pipe, it becomes easy to apply a rotational torque to the center part by applying a tool to the center part. For this reason, the first threaded part and the second threaded part can be easily threaded into the existing inner pipe and the new inner pipe, compared to the case where the outer periphery of the central part does not have a two-sided part.

A connecting tool for replacing pipes according to a seventh aspect is the connecting tool for replacing pipes according to the fifth aspect or the sixth aspect, wherein a hole for hanging a tool is formed in the center part.

The connecting tool for pipe replacement has a hole on the outer periphery of the center portion for hanging a tool. Thereby, when screwing the first threaded part and the second threaded part into the existing inner pipe and the newly installed inner pipe, it becomes easy to apply a rotational torque to the center part by applying a tool to the center part. For this reason, the first threaded part and the second threaded part can be easily threaded into the existing inner pipe and the newly installed inner pipe, compared to the case where the central part does not have a hole.

According to the present invention, there is provided a pipe replacement method that can reduce the labor required for pipe replacement in a pipe replacement work in which an existing inner pipe inserted into a protection tube is replaced with a new inner pipe. .

FIG. 1 is a schematic diagram showing an example of a piping structure in which a piping replacement method according to an embodiment is used. FIG. 2 is a front view showing a connector used in the pipe replacement method according to the embodiment. FIG. 3 is a cross-sectional view showing a connector used in the pipe replacement method according to the embodiment. It is a figure which shows a mode that the existing inner pipe and the new inner pipe are connected at the other end side of a protection pipe in the pipe replacement method based on embodiment. It is a figure which shows a mode that lubricant is attached to the existing internal pipe|tube at the other end side of a protection pipe in the piping replacement method based on embodiment. FIG. 6 is a diagram illustrating how a new inner pipe is pushed in at the other end of the protection tube while pulling the existing inner pipe at one end of the protection tube in the pipe replacement method according to the embodiment. In the pipe replacement method according to the embodiment, while pulling the existing inner pipe at one end of the protection tube, a new inner pipe is pushed in at the other end of the protection tube, and the figure shows how the new inner pipe is being inserted. It is. FIG. 6 is a diagram illustrating a state in which the new inner pipe is inserted by pushing the new inner pipe at the other end of the protection tube while pulling the existing inner pipe at one end of the protection tube in the pipe replacement method according to the embodiment. .

An example of an embodiment of the present disclosure will be described below with reference to the drawings. In addition, in each drawing, the same reference numerals are given to the same or equivalent components and parts. Furthermore, the dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual ratios.

(Hot water system 70, double pipe 20)
FIG. 1 is a schematic diagram showing a hot water supply system 70, which is an example of a piping structure to which the piping replacement method according to the present embodiment is applied. In this hot water supply system 70, as shown in FIG. 1, a storage tank 80 is arranged on one side of the building 72 (on the left side of the paper in FIG. 1), and a heating device 78 is arranged on the other side of the building 72 (on the right side of the paper in FIG. 1). At the same time, a double pipe 20 connects the heating device 78 and the storage tank 80.

In addition, as shown in FIG. It has a protective tube 26 that protects the inner tube 22.

The protective tube 26 is made of a hard resin such as polyethylene, polypropylene, or polyamide resin, for example, and has an annular peak portion that is convex toward the outside in the radial direction and an annular valley portion that is concave on the outside in the radial direction alternately. It is a tube body (corrugated tube) that has flexibility due to its formation. Further, the outer diameter and thickness of the protective tube 26 are not particularly limited, but as an example, the outer diameter is set to 18 mm or more and 130 mm or less, and the thickness is set to 0.5 mm or more and 2.0 mm or less. Note that the protection tube 26 is fixed to a wall material 74 of the building 72 by a holder (not shown).

The existing inner tube 22 is, for example, a tube body made of multilayer resin, having an outer diameter of 14.6 mm, an inner diameter of 10.0 mm, and a bending elastic modulus of 50 MPa or more and less than 150 MPa. This existing inner pipe 22 is held by being inserted into the protection pipe 26, and both ends are connected to the heating device 78 and the storage tank 80. In addition, the measurement of the bending elastic modulus is based on JIS K7171:2022, as an example.

Further, the existing inner pipe 22 is an example of one pipe body according to the present disclosure.

In the hot water system 70 as shown in FIG. 1, the double pipe 20 avoids the living room 76 inside the building 72 and is piped inside the building 72 along the wall material 74 of the building 72, so that the double pipe 20 is connected to the heating device 78. A curved portion occurs in the pipe line of the double pipe 20 that connects the storage tank 80. In this case, in order to replace the existing inner pipe 22 with a new inner pipe 24 to be described later, even if the existing inner pipe 22 is pulled from either the heating device 78 or the storage tank 80 side, the outer peripheral surface of the existing inner pipe 22 Because the curved portion rubs against the inner peripheral surface of the protective tube 26, it is difficult to pull out the existing inner tube 22.

Here, in the pipe replacement method according to the present embodiment, the existing inner pipe 22 is replaced with a new inner pipe 24 using a connector 30 shown below.

(Connection tool 30)
FIG. 2 is a diagram illustrating an example of a connector 30 for replacing pipes according to the present disclosure, and FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. As shown in FIGS. 2 and 3, the connector 30 according to the present embodiment includes a substantially cylindrical center portion 32 and a surface on one side (left side in FIG. 2) with respect to the axis C of the center portion 32. It has a first threaded portion 34 extending from the central portion 32 and a second threaded portion 36 extending from the surface of the center portion 32 on the opposite side to the first threaded portion 34 (the right side in the drawing in FIG. 2).

Furthermore, as shown in FIGS. 2 and 3, the outer peripheral surface of the central portion 32 is formed with a two-sided portion 32P having a pair of flat portions 32A sandwiched therebetween in the radial direction. This two-sided portion 32P is a portion on which a tool such as a wrench can be hung in a connection process to be described later. In other words, the two-sided portion 32P is also a torque receiving portion that receives rotational torque from a tool such as a wrench.

Further, as shown in FIGS. 2 and 3, a hole 32H is formed in the central portion 32 so as to communicate between the pair of flat portions 32A. This hole 32H is a portion into which a rod-shaped tool can be inserted and hung in a connection process to be described later. In other words, the hole 32H is also a torque receiving part that receives rotational torque from a rod-shaped tool.

Note that the length and diameter of the central portion 32 in the direction of the axis C are appropriately designed in accordance with the protective tube 26, but as an example, the length in the direction of the axis C is 10 mm, and the diameter is 14.5 mm. . Further, the interval between the two-sided portions 32P is, for example, 12 mm.

As shown in FIG. 2, the first threaded part 34 is a tapered part extending from the central part 32, and has a male threaded part 34M formed on its outer peripheral surface. The male threaded portion 34M is, for example, a right-handed thread, and can be inserted into the inner circumferential surface of the existing inner pipe 22 in the connection process described later.

The length of the first threaded portion 34 in the direction of the axis C, the size of the diameter, the pitch of the external thread, and the taper angle are appropriately designed according to the existing inner pipe 22. The length is 15 mm, the maximum diameter is 11.4 mm, the pitch of the male threaded portion 34M is 2 mm, and the taper angle is 3.24°. Further, the width of the tip of the thread of the male threaded portion 34M is appropriately designed in accordance with the existing inner pipe 22, and is, for example, 0.2 mm or less. Further, the height of the thread of the male threaded portion 34M is, for example, 1 mm, and the angle of the thread of the male threaded portion 34M is 30°.

As shown in FIG. 2, the second threaded part 36 is a tapered part extending from the center part 32 to the opposite side of the first threaded part 34, and has a first threaded part on its outer peripheral surface. A reverse male threaded portion 36M is formed which is a reverse thread (left-hand thread) from the male threaded portion 34M of the portion 34. Like the male threaded portion 34M, this reverse male threaded portion 36M can be inserted into the inner circumferential surface of the newly installed inner pipe 24 in the connection process described later.

Note that the specific shape of the second threaded portion 36 is, for example, the same as that of the first threaded portion 34.

From another perspective, it can be said that the second threaded portion 36 is a portion that is plane symmetrical to the first threaded portion 34 with the center portion 32 as the center.

Further, the connector 30 may be made of any material, but is made of metal such as brass or bronze, for example.

Note that, as shown in FIG. 3, the connector 30 is a solid body as an example, but it may also be a hollow body (tubular body) that communicates from the first screwed part 34 to the second screwed part 36. good.

(Piping replacement procedure)
Next, the procedure for replacing piping according to this embodiment will be explained with reference to FIGS. 4 to 8 as appropriate. Note that in FIGS. 4 to 8, the protection tube 26 is illustrated as having a linearly extending shape for the sake of explanation, but the protection tube 26 is not limited to this, and may have a curved portion.

Note that the newly installed inner pipe 24 described in this pipe replacement procedure is a pipe body to be replaced with the existing inner pipe 22 described above, and has the same shape and physical properties as the existing inner pipe 22. In other words, it is a tube body that has flexibility like the existing inner tube 22 and can be inserted into the protection tube 26.

Moreover, the newly installed inner pipe 24 is an example of another pipe body according to the present disclosure.

(Connection process)
First, in the connecting step, the other end 22R of the existing inner pipe 22 and one end 24L of the newly installed inner pipe 24 are connected using the connector 30.

FIG. 4 is a diagram showing a connection process of connecting the other end 22R of the existing inner pipe 22 and one end 24L of the newly installed inner pipe 24 with the connector 30, and shows the one end 26L side of the protection tube 26 (leftward on the page). The existing inner pipe 22 is inserted from the end to the other end 26R side (rightward in the drawing). In addition, in FIG. 4, the existing inner pipe 22 is in a state where it has been removed from the heating device 78 and the storage tank 80, and both ends are exposed from the protection pipe 26. As shown in FIG. 4, in the connection process, the connector 30 is sandwiched between the other end 22R of the existing inner pipe 22 and one end 24L of the newly installed inner pipe 24.

More specifically, in the state shown in FIG. 4, the first threaded part 34 of the connector 30 is inserted into the other end 22R of the existing inner pipe 22, and the second threaded part 36 is inserted into the one end 24L of the newly installed inner pipe 24. is inserted into.

Subsequently, a tool such as a wrench is hung on the two-sided portion 32P of the central portion 32 of the connector 30, and the connector 30 is rotated about the axis C. In this state, the male threaded portion 34M of the first threaded portion 34 is inserted into the inner peripheral surface of the existing inner pipe 22, and the reverse male threaded portion 36M of the second threaded portion 36 is inserted into the inner peripheral surface of the newly installed inner pipe 24, respectively.

Then, the first threaded part 34 and the second threaded part 36 are inserted into the inner peripheral surfaces of the existing inner pipe 22 and the new inner pipe 24, respectively, so that the existing inner pipe 22 and the new inner pipe 24 are connected.

(insertion process)
In the insertion step, while attaching lubricant 28 to the outer peripheral surfaces of the existing inner tube 22 and the new inner tube 24 on the other end 26R side of the protection tube 26, insert the lubricant 28 from the other end 26R side of the protection tube 26 toward the one end 26L side. Insert the new inner pipe 24.

FIG. 5 is a diagram showing how the lubricant 28 is attached to the other end 22R of the existing inner pipe 22. As shown in FIG. 5, a lubricant 28 is applied to the existing inner tube 22 exposed from the other end 26R side of the protective tube 26. This lubricant 28 may be of any kind, but one example is a silicone lubricant.

FIG. 6 is a diagram showing how the existing inner tube 22 or the new inner tube 24 is pushed in from the other end 26R side of the protection tube 26 while pulling the existing inner tube 22 from one end 26L side of the protection tube 26. As shown in FIG. 6, in the piping replacement method according to this embodiment, the existing inner pipe 22 is pulled at one end 26L side of the protection tube 26, and the other end 22R of the existing inner pipe 22 is pulled at the other end 26R side of the protection tube 26. Push in at the same time. That is, the existing inner tube 22 is pulled at one end 26L of the protection tube 26 while the other end 22R is pushed into the protection tube 26.

As a result, the existing inner tube 22 is pulled out toward one end 26L of the protection tube 26, while the other end 22R is pushed into the protection tube 26. The newly installed inner tube 24 connected to the other end 22R of the existing inner tube 22 is also subsequently pushed into the protection tube 26.

In this state, on the other end 26R side of the protection tube 26, the existing inner tube 22 or the newly installed inner tube 24 continues to have the lubricant 28 adhered to its outer peripheral surface.

FIG. 7 is a diagram showing how the other end 22R of the existing inner tube 22 and one end 24L of the newly installed inner tube 24 have entered the protection tube 26. As shown in FIG. 7, the other end 22R of the existing inner pipe 22 and one end 24L of the new inner pipe 24 are connected by the connector 30, so that they are connected to each other from the other end 26R side of the protective tube 26 to the one end 26L side. move towards.

FIG. 8 is a diagram showing how the other end 22R of the existing inner tube 22 and the one end 24L of the newly installed inner tube 24 have moved to the one end 26L side of the protection tube 26. As shown in FIG. 8, when the other end 22R of the existing inner tube 22 moves to the one end 26L side of the protection tube 26, the one end 24L of the newly installed inner tube 24 moves to the one end 26L side of the protection tube 26. In other words, the newly installed inner tube 24 is inserted into the protective tube 26 at the same time as the existing inner tube 22 is removed from the protective tube 26 .

In this state, the pulling of the existing inner pipe 22 on the one end 26L side of the protective tube 26 and the pushing of the new inner pipe 24 on the other end 26R side of the protective tube 26 are stopped, and the connecting tool 30 is rotate in the opposite direction. As a result, the first threaded part 34 is removed from the existing inner pipe 22, and the second threaded part 36 is removed from the newly installed inner pipe 24.

In this state, the inner circumferential surface of the one end 24L of the newly installed inner tube 24 may be damaged by the reverse male threaded portion 36M of the second threaded portion 36 due to biting. In this case, by cutting a length corresponding to the second threaded portion 36 from one end 24L of the newly installed inner pipe 24, the damaged portion on the inner circumferential surface is removed.

Thereafter, by connecting both ends of the newly installed inner pipe 24 to the heating device 78 and the storage tank 80, the replacement of the inner pipe of the double pipe 20 of the hot water supply system 70 shown in FIG. 1 is completed.

In the above explanation, a tool such as a wrench is hung on the two-sided portion 32P of the central portion 32 to rotate the connector 30, but instead of this, a rod-shaped tool is inserted into the hole 32H of the central portion 32. However, the connecting tool 30 may be rotated using a rod-shaped tool. Whether a tool such as a wrench or a rod-shaped tool is used to rotate the connecting tool 30 is determined as appropriate depending on the material and shape of the existing inner pipe 22 and the new inner pipe 24.

(action and effect)
The piping replacement method and connector 30 according to this embodiment provide the following actions and effects.

In the piping replacement method according to the present embodiment, the existing flexible inner pipe 22 inserted from one end 26L side of the protection tube 26 to the other end 26R side is replaced with a new flexible inner pipe 24. In the piping replacement method, a connecting step of connecting the other end 22R of the existing inner pipe 22 and one end 24L of the new inner pipe 24 with a connector 30 on the other end 26R side of the protection pipe 26; The method includes an insertion step of inserting the newly installed inner tube 24 into the protective tube 26 from the other end 26R side of the protective tube 26 while pulling out the existing inner tube 22 from the side.

After connecting the existing inner tube 22 inserted into the protection tube 26 and the new inner tube 24 with the connector 30, the new inner tube 24 is pulled out while pulling out the existing inner tube 22 from one end 26L side of the protection tube 26. It is inserted. As a result, in the piping replacement work in which the existing inner tube 22 inserted into the protection tube 26 is replaced with the new inner tube 24, the new inner tube 24 is inserted while pulling out the existing inner tube 22 from the one end 26L side of the protection tube 26. Compared to a replacement method that does not include an insertion process, the labor required for replacing the piping can be reduced.

Further, in the pipe replacement method according to the present embodiment, the insertion step is performed while applying the lubricant 28 to the outer peripheral surface of the existing inner pipe 22 or the new inner pipe 24 on the other end 26R side of the protection tube 26.

In the insertion step, the lubricant 28 is applied to the outer peripheral surface of the existing inner tube 22 or the new inner tube 24 on the other end 26R side of the protective tube 26. Thereby, the frictional resistance between the inner circumferential surface of the protection tube 26 and the outer circumferential surface of the existing inner tube 22 and the outer circumferential surface of the newly installed inner tube 24 can be reduced.

Further, in the pipe replacement method according to the present embodiment, the insertion step includes protecting the existing inner pipe 22 while pushing the existing inner pipe 22 or the new inner pipe 24 into the protection pipe 26 on the other end 26R side of the protection pipe 26. This is done by pulling out the tube 26 from one end 26L side.

In the insertion process, the existing inner tube 22 and The newly installed inner pipe 24 is prevented from being excessively stretched or excessively loosened. As a result, by pulling out the existing inner tube 22 from the one end 26L side of the protection tube 26 while keeping the existing inner tube 22 and the new inner tube 24 appropriately loosened inside the protection tube 26, such insertion can be carried out. Compared to a pipe replacement method that does not involve a process, it is possible to reduce the frictional resistance between the outer peripheral surface of the existing inner pipe 22 and the outer peripheral surface of the new inner pipe 24 and the protection pipe 26 when replacing the pipe. can.

In addition, in the pipe replacement method according to the present embodiment, the connecting tool 30 extends from the central portion 32 and one side surface with respect to the axis C of the central portion 32 while having a male threaded portion 34M, and has a male threaded portion 34M. The first screwed part 34 is screwed into the inner peripheral surface of the new inner pipe 24 at one end 24L of the 24, and the male screwed part 34M is screwed from the opposite side of the first screwed part 34 with respect to the axis C of the central part 32. The second threaded part 36 extends while having a reverse male threaded part 36M formed in the opposite direction, and is screwed into the inner circumferential surface of the existing inner pipe 22 at the other end 22R of the existing inner pipe 22.

The connector 30 has a first threaded portion 34 and a second threaded portion 36 having a reverse male threaded portion 36M that is a reverse thread than the male threaded portion 34M of the first threaded portion 34. As a result, the first threaded part 34 can be screwed into the new inner pipe 24 and the second threaded part 36 can be threaded into the existing inner pipe 22 at the same time. The workability of connections can be improved.

Moreover, even if either the first threaded part 34 or the second threaded part 36 of the connecting tool 30 becomes loose when the existing inner pipe 22 or the new inner pipe 24 is twisted inside the protection tube 26, the other one is Tighten. Therefore, compared to the case where a reverse thread is not used, it is possible to prevent the connector 30 from falling off both the existing inner pipe 22 and the new inner pipe 24 inside the protection tube 26. Furthermore, even if the connector 30 falls off from either the existing inner pipe 22 or the new inner pipe 24, it will not fall off from the other, so by pulling out the existing inner pipe 22 or the new inner pipe 24, The connector 30 can be taken out from the protective tube 26.

Furthermore, the connecting tool 30 according to the present embodiment has two parallel surfaces 32P on the outer periphery of the central portion 32, on which a tool can be hung.

The connecting tool 30 has two parallel surfaces 32P on the outer periphery of the central portion 32 for hanging tools. Thereby, when screwing the first threaded part 34 and the second threaded part 36 into the existing inner pipe 22 and the newly installed inner pipe 24, it becomes easy to apply a rotational torque to the center part 32 by applying a tool to the center part 32. For this reason, the first threaded part 34 and the second threaded part 36 are made easier to screw into the existing inner pipe 22 and the new inner pipe 24, compared to the case where the central part 32 does not have the two-sided part 32P on the outer periphery. be able to.

Furthermore, the connecting tool 30 according to this embodiment has a hole 32H formed in the center portion 32 for hanging a tool.

The connector 30 has a hole 32H on the outer periphery of the central portion 32 for hanging a tool. Thereby, when screwing the first threaded part 34 and the second threaded part 36 into the existing inner pipe 22 and the newly installed inner pipe 24, it becomes easy to apply a rotational torque to the center part 32 by applying a tool to the center part 32. Therefore, compared to the case where the central part 32 does not have the hole 32H, the first screwed part 34 and the second screwed part 36 can be easily screwed into the existing inner pipe 22 and the new inner pipe 24. .

(Modified example)
In the above description, the connecting tool 30 has two parallel surfaces 32P and a hole 32H for hanging a tool, but it may have a shape in which only one of the two surfaces 32P or the hole 32H is formed. may have been done. In this case as well, the connector 30 can be connected to the existing inner pipe 22 and the new inner pipe 24 using either the two-sided portion 32P or the hole 32H formed in the central portion 32.

Furthermore, in the above description, the connector 30 had the two-sided portion 32P for hanging a tool and the hole 32H for hanging a tool, but the connector 30 according to the present embodiment is not limited to this. For example, if the first threaded part 34 can be screwed into the existing inner pipe 22 and the second threaded part 36 can be threaded into the newly installed inner pipe 24 by grasping the center part 32 by hand, then the second threaded part 32P and the hole 32H may not be formed.

In addition, in the above description, as shown in FIG. 2, the first threaded part 34 and the second threaded part 36 of the connecting tool 30 are respectively tapered as a whole, but the connecting tool according to the present embodiment 30 is not limited to this. For example, the tapered shape may be formed only in a part of the first threaded part 34 or the second threaded part 36, or the first threaded part 34 or the second threaded part 36 may have a shape without a taper. may have been done.

Furthermore, in the above description, the pipe replacement method used the connector 30 having the central portion 32, the first threaded part 34, and the second threaded part 36, but the pipe replacement method according to the present disclosure uses this. but not limited to. For example, the existing inner pipe 22 and the newly installed inner pipe 24 may be connected using an adhesive or the like without using the connector 30.

Furthermore, in the above explanation, the piping replacement method involves applying the lubricant 28 to the existing inner pipe 22 and the new inner pipe 24 on the other end 26R side of the protection tube 26, but the piping replacement method according to the present disclosure , but not limited to. For example, the frictional resistance between the inner circumferential surface of the protection tube 26 and the outer circumferential surfaces of the existing inner tube 22 and the new inner tube 24 is small, and the tension of the existing inner tube 22 and the new inner tube 24 can be maintained without adhering the lubricant 28. If it is possible to press the lubricant 28, the attachment of the lubricant 28 may be omitted.

In addition, in the above explanation, the piping replacement method is such that while pulling the existing inner pipe 22 on the one end 26L side of the protection tube 26, the other end 22R of the existing inner pipe 22 or the new inner pipe is pulled on the other end 26R side of the protection tube 26. Although one end 24L of 24 is pushed in, the piping replacement method according to the present disclosure is not limited to this. For example, the frictional resistance between the inner circumferential surface of the protective tube 26 and the outer circumferential surfaces of the existing inner tube 22 and the new inner tube 24 is small, and by pulling the existing inner tube 22 from the other end 26R side of the protective tube 26, If it is possible to insert the inner tube 24 into the protection tube 26, pushing the existing inner tube 22 and the new inner tube 24 on the other end 26R side of the protection tube 26 may be omitted. In addition, by pulling the existing inner pipe 22 at one end 26L side of the protection tube 26 and pushing in the existing inner pipe 22 and the new inner pipe 24 at the other end 26R side of the protection tube 26, the existing inner pipe 22 As long as it is possible to move from the other end 26R side to the one end 26L side, it is not necessary to pull and push at the same time.

Further, in the above description, the protective tube 26 was formed of hard resin, but the pipe replacement method according to the present disclosure is not limited to this. For example, the protection tube 26 may be a tube body made of a soft material such as foamed polyethylene used as a heat insulating material.

Further, in the above description, the piping structure is a double pipe 20 having the existing inner pipe 22 and the protection pipe 26, but the piping replacement method according to the present disclosure is not limited to this. For example, the protection tube 26 may have a structure in which more layers are stacked than in the above description. In this case, the other tubes excluding the outermost tube may be considered and applied as the existing inner tube 22 according to the present disclosure, and only the innermost tube may be used as the existing inner tube 22 according to the present disclosure. It may be considered and applied.

Although the embodiments of the present disclosure have been described above with reference to the accompanying drawings, those with ordinary knowledge in the technical field to which the present disclosure pertains will understand that the embodiments are within the scope of the technical idea described in the claims. It is clear that various modifications or applications can be made, and it is understood that these naturally fall within the technical scope of the present disclosure.

20 Double pipe, 22 Existing inner pipe (an example of the first pipe body), 24 Newly installed inner pipe (an example of another pipe body), 26 Protection pipe, 28 Lubricant, 30 Connector, 32 Central part, 34 No. 1 screwed part, 36 2nd screwed part, 70 hot water supply system, 72 building, 74 wall material, 76 living room, 78 heating device, 80 storage tank

Claims (7)

In a piping replacement method in which an existing flexible inner pipe inserted from one end of a protection tube to the other end is replaced with a new flexible inner pipe,
a connecting step of connecting the other end of the existing inner pipe and one end of the new inner pipe with a connector on the other end side of the protection pipe;
an insertion step of inserting the new inner tube into the protection tube from the other end of the protection tube while pulling out the existing inner tube from one end of the protection tube;
A piping replacement method. The insertion step is performed while applying a lubricant to the outer peripheral surface of the existing inner tube or the new inner tube at the other end of the protective tube.
The piping replacement method according to claim 1. The insertion step is performed by pulling out the existing inner tube from one end of the protective tube while pushing the existing inner tube or the new inner tube into the protective tube at the other end of the protective tube.
The piping replacement method according to claim 1. The connecting tool extends from a central portion and a surface on one side with respect to the axis of the central portion, and has a male threaded portion, and is screwed into the inner circumferential surface of the newly installed inner pipe at one end of the newly installed inner pipe. a first threaded part extending from a surface opposite to the first threaded part with respect to the axis of the central part, and a reverse male threaded part formed in a direction opposite to the male threaded part; a second threaded part screwed into the inner circumferential surface of the existing inner pipe at the other end of the existing inner pipe;
The piping replacement method according to any one of claims 1 to 3. The central part and
a first threaded part that extends from one side with respect to the axis of the central part and has a male threaded part and is screwed into the inner circumferential surface of the first tube body;
an inner circumferential surface of another tube extending from a surface opposite to the first threaded part with respect to the axis of the central part while having a reverse male threaded part formed in a direction opposite to the male threaded part; a second screwed part screwed into the
Connecting tool for piping replacement, with 6. The connector according to claim 5, further comprising two parallel surfaces on the outer periphery of the central portion for hanging tools. The connector according to claim 5 or 6, wherein a hole for hanging a tool is formed in the center portion.