JP2019218981A - Manufacturing method of pipes for non-drilling new pipe laying method and update method of underground laying pipe - Google Patents

Abstract

To provide a manufacturing method of pipes for non-drilling new pipe laying method that is capable of improving the construction quality.SOLUTION: A manufacturing method of pipes for non-drilling new pipe laying method, comprises the steps of: preparing a plurality of pipe members 12 having a protective layer 22 on the outer peripheral surface of a polyolefin resin pipe body 20; peeling off the protective layer of the ends of the pipe members; connecting, by butt fusion, the ends of the pipe members from which the protective layer has been peeled off; and attaching a protective member 24 to the part where the protective layer of the connected pipe member has been peeled off.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for producing a pipe for a non-drilling new pipe laying method and a method for updating an underground pipe. It relates to a method of updating underground pipes.

  Non-Patent Document 1 discloses an example of a conventional method of updating a gas pipe without cutting. The method of Non-Patent Document 1 is a method of replacing a ductile cast iron pipe (existing pipe) having a diameter of 150 to 200 mm with a polyethylene pipe (new pipe) of the same diameter without cutting. In this method, an existing ductile cast iron pipe is cut in the axial direction using a cutting diameter expander, and a polyethylene pipe is drawn into and inserted into the ductile cast iron pipe while expanding the diameter.

  In the method of Non-Patent Document 1, since a newly installed pipe having a diameter of 150 to 200 mm is used, it is difficult to wind a long newly installed pipe into a roll and carry it to the construction site. For this reason, after a plurality of pipe members of a predetermined length are carried into a construction site, pipe ends of the pipe members are butt-fused to each other at the construction site to extend to a required length.

Toho Gas Co., Ltd., “STREAM method (stream method)”, [online], [searched on June 11, 2018], Internet <URL: http://www.tohogas.co.jp/approach/technologies/technologies -supply / open-cut / open-cut-07 / ＞

  In the non-cutting method as disclosed in Non-Patent Document 1, the outer peripheral surface of the new pipe is damaged when the new pipe is drawn into the existing pipe, and the long-term durability against gas pressure (internal pressure) remains uneasy. There were concerns about the construction quality. Here, in order to prevent the new pipe from being damaged, it is conceivable to provide a protective layer on the outer peripheral surface of the pipe body of the new pipe in advance. However, it is difficult to determine whether or not the pipe bodies are properly fused, and it is difficult to extend the pipe member having the protective layer by butt fusion as it is.

  SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a method for producing a new pipe for a new non-cutting new pipe laying method and a method for updating an underground pipe.

  Another object of the present invention is to provide a method for manufacturing a pipe for laying a non-drilling new pipe and a method for updating an underground pipe, which can improve the construction quality.

  The first invention is a method for producing a pipe for a non-drilling new pipe laying method laid in the ground by a non-drilling method, wherein (A) a pipe having a protective layer on an outer peripheral surface of a pipe body made of a polyolefin resin. (B) peeling off the protective layer at the end of the tubular member, and (C) connecting the tubular ends of the tubular member from which the protective layer was removed in step (B) by butt fusion. And (D) attaching a protective member to a portion of the pipe member connected in step (C) from which the protective layer has been peeled off, the method comprising the steps of: is there.

  In the first invention, first, in step (A), a number of pipe members corresponding to the length required for construction are prepared. This pipe member has a protective layer on the outer peripheral surface of a pipe body made of polyolefin resin. In step (B), the protective layer at the end of the tube member is peeled off by a predetermined length. In the step (C), the pipe ends of the pipe members from which the protective layer has been peeled off are connected by butt fusion. As described above, by performing butt fusion in a state where the protective layer at the pipe end is removed and the pipe main body is exposed, it is possible to easily confirm that the pipe main bodies are properly welded to each other. . Then, in step (D), a protection member is attached to the portion of the tube member from which the protection layer has been peeled off. Since the outer peripheral surface of the pipe for the non-drilling new pipe laying method manufactured in this manner is covered with the protective layer and the protective member, the pipe body is appropriately prevented from being damaged during construction.

  According to the first aspect of the invention, it is possible to produce a pipe for a non-drilling new pipe laying method that can appropriately weld the pipe bodies to each other and prevent the pipe body from being damaged during construction. Therefore, gas pipes and the like formed by using the pipes for the non-cutting new pipe laying method can maintain the durability against the internal pressure for a long period of time, and the construction quality is improved and stabilized.

  A second invention is according to the first invention, and in the step (D), the protective layer peeled off in the step (B) is used as a protective member.

  According to the second invention, it is costly to separately manufacture a protection member for covering the exposed portion of the tube main body, and it is not easy to manufacture a protection member suitable for the exposed portion. By using the layer as a protective member, the manufacturing cost of the protective member can be reduced, and the protective member can be adapted to the exposed portion of the tube body.

  A third invention is according to the first or second invention, and includes a step of removing a bead generated by butt fusion after step (C) and before step (D).

  According to the third aspect of the present invention, the bead formed at the connection portion of the pipe member is removed and smoothed, so that the protection member is less likely to be damaged at the time of construction, and thus the pipe body is more reliably prevented from being damaged. .

  The fourth invention is an underground pipe renewing method for renewing an existing pipe laid in the ground to a new synthetic resin pipe by a non-cutting method, wherein (a) a pipe body made of a polyolefin resin A step of preparing a plurality of pipe members having a protective layer on the outer peripheral surface; (b) a step of peeling off the protective layer at an end of the pipe member; and (c) a pipe of the pipe member in which the protective layer is peeled off in step (b). (D) connecting the ends by butt fusion, (d) attaching a protective member to the portion of the tube member connected in step (c) from which the protective layer has been peeled off, and fabricating a new pipe. e) A method of updating an underground pipe, including a step of inserting a new pipe into an existing pipe.

  In the fourth invention, first, in step (a), a number of pipe members corresponding to the length required for construction are prepared. This pipe member has a protective layer on the outer peripheral surface of a pipe body made of polyolefin resin. In step (b), the protective layer at the end of the tube member is peeled off by a predetermined length. In step (c), the pipe ends of the pipe members from which the protective layer has been peeled off are connected by butt fusion. In this manner, by performing the pad fusion in a state where the protective layer at the pipe end is removed and the pipe main body is exposed, it is possible to easily confirm that the pipe main bodies are properly welded to each other. . Further, in step (d), a protection member is attached to a portion of the tube member from which the protection layer has been peeled off, and a new pipe is manufactured. Then, in step (e), the new pipe is inserted into the existing pipe. At this time, since the outer peripheral surface of the new pipe is covered with the protective layer and the protective member, the pipe main body is appropriately prevented from being damaged.

  According to the fourth aspect, similarly to the first aspect, the pipe bodies are appropriately welded to each other, and the pipe bodies can be prevented from being damaged during construction. Underground pipes that can be maintained can be formed, and the construction quality of underground pipes can be improved and stabilized.

  A fifth invention is according to the fourth invention, and in the step (d), the protective layer peeled off in the step (b) is used as a protective member.

  According to the fifth aspect, as in the second aspect, by using the peeled-off protective layer as a protective member, the production cost of the protective member can be reduced, and the protective member can be provided on the exposed portion of the pipe main body. It can be adapted.

  A sixth invention is according to the fourth or fifth invention, wherein the new pipe is a pipe having the same diameter as the existing pipe, and in step (e), the existing gas pipe is pivoted by using a cutting and expanding device. While cutting in the direction and expanding the diameter, a new pipe is inserted into the existing pipe.

  According to the sixth aspect, the existing pipe can be appropriately replaced with a new pipe having the same diameter.

  ADVANTAGE OF THE INVENTION According to this invention, the pipe body for non-opening new pipe laying method which can prevent a pipe body from being appropriately welded to each other and preventing the pipe body from being damaged during construction can be produced. Therefore, gas pipes and the like formed by using the pipes for the non-cutting new pipe laying method can maintain the durability against the internal pressure for a long period of time, and the construction quality is improved and stabilized.

  The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

It is a perspective view showing an example of a pipe member. It is sectional drawing which shows the pipe member of FIG. FIG. 2 is an illustrative view schematically showing a method for manufacturing a gas pipe according to one embodiment of the present invention; FIG. 4 is an illustrative view schematically showing a step following FIG. 3; FIG. 5 is an illustrative view showing a state in which an existing gas pipe is updated using a new pipe manufactured by the method for manufacturing a gas pipe shown in FIGS. 3 and 4.

  The method for manufacturing a gas pipe (an example of a pipe for a non-cutting new pipe laying method) according to an embodiment of the present invention is a method for manufacturing a long pipe made of a polyolefin resin used as a gas pipe. In this method of manufacturing a gas pipe, as described in detail later, a plurality of pipe members 12 of a predetermined length are butt-fused at a construction site to obtain a gas pipe 10 of a required length. This gas pipe 10 is a pipe laid underground by a non-cutting method, and in this embodiment, as shown in FIG. 5, for a medium pressure B (gas pressure is less than 0.1 MPa to less than 0.3 MPa). It is used as a new pipe (renewal pipe) for replacing the ductile cast iron pipe 100 which is an existing gas pipe with the same diameter.

  First, the pipe member 12 for producing the gas pipe 10 will be described. As shown in FIGS. 1 and 2, the pipe member 12 is a straight pipe having a two-layer structure having a pipe main body 20 and a protective layer 22 covering the entire outer peripheral surface thereof. The diameter of the tube member 12 is, for example, 50-250 mm, and the tube length is, for example, 5000-5500 mm.

  The pipe main body 20 is an inner layer pipe that constitutes a gas pipe, that is, has an essential performance as a gas pipe, and is formed of a polyolefin resin such as a medium density polyethylene and a high density polyethylene. The tube main body 20 is formed by extrusion or the like.

  The protective layer 22 is an outer layer tube for protecting the tube body 20 from external damage, and is formed of a synthetic resin such as a polyolefin resin. In this embodiment, the protective layer 22 is formed of low-density polyethylene in consideration of material costs. The outer peripheral surface of the protective layer 22 may be coated with a material having low friction. This is because if the outer peripheral surface of the protective layer 22 is made smooth, it is less likely to be damaged during construction.

  The thickness of the protective layer 22 can be appropriately set, but is preferably 1 mm or more and 2 mm or less. According to the construction experiment of the inventor of the present application, the depth of the damage of the protection layer 22 due to the rubbing with the existing pipe or the ground is less than 1 mm, and if the thickness of the protection layer 22 is 1 mm or more, the damage of the pipe main body 20 is reduced. This is because it has been confirmed that it can be appropriately prevented. In addition, if the thickness of the protective layer 22 is increased for the purpose of providing a margin, the material cost is increased, and if the thickness of the protective layer 22 exceeds 2 mm, the workability when the protective layer 22 is peeled off as described later. Is worse. In this embodiment, the thickness of the protective layer 22 is 1.5 mm.

As a method of covering the outer peripheral surface of the tube main body 20 with the protective layer 22, for example, a method of extruding and covering a resin to be the protective layer 22 through a mold outside the tube main body 20 (extrusion coating) may be used. Also, a method of welding a sheet-shaped protective member to be the protective layer 22 to the outer peripheral surface of the tube main body 20 or a method of forming the pipe main body in a tubular protective member slightly larger than the tube main body 20 to be the protective layer 22. After passing through 20, a method of shrinking the protection member by heat can also be used. In the pipe member 12 manufactured in this manner, the pipe body 20 and the protective layer 22 are fixed in close contact with each other, but since these are configured separately, the protective layer 22 can be easily separated from the pipe body 20. Can be peeled off. Further, since the pipe main body 20 and the protective layer 22 are separate bodies, even if the protective layer 22 is damaged, the influence is prevented at these boundaries and is hard to reach the pipe main body 20.

Hereinafter, a method for manufacturing the gas pipe 10 using the above-described pipe member 12 will be described with reference to FIGS. First, as shown in FIG. 3A, a plurality of pipe members 12 are carried into a construction site. 3 and 4, two pipe members 12 are shown for simplicity. However, actually, a number of pipe members 12 according to the length required for construction are prepared, and adjacent pipe members 12 are provided. Of the pipes are sequentially butt-fused by a method described later. Next, as shown in FIG. 3B, the protective layer 22 at the end of the tube member 12 is peeled off. When the protective layer 22 is peeled off, for example, the protective layer 22 may be cut in a circumferential direction at a predetermined length from the pipe end, and then the protective layer 22 on the end side may be cut in the pipe axis direction. Here, the length from which the protective layer 22 is peeled off may be any length as long as at least the end of the tube main body 20 is exposed and it is possible to confirm that the tube main bodies 20 are properly fused to each other. The length is such that the pipe fixing portion 52 of the butt fusion machine 50 can directly clamp the pipe main body 20. This is because the pipe fixing portion 52 directly clamps the pipe main body 20, thereby increasing the accuracy in centering the pipe members 12. In this embodiment, the protective layer 22 in a portion of the pipe member 12 from the pipe end to 150 mm is peeled off. Further, the protective layer 22 peeled off, that is, the short cylindrical protective layer 22 cut in the tube axis direction is stored as it is used as the protective member 24 as described later.

  Subsequently, as shown in FIG. 3C, the tube ends of the tube members 12 from which the protective layer 22 has been removed are connected by butt fusion using a butt fusion machine 50. In this embodiment, a bat fusion machine having four pipe fixing parts 52 is used, and each pipe main body 20 is directly clamped by the two pipe fixing parts 52 at the center in the axial direction. As described above, by removing the protective layer 22 at the end of the tube member 12 and performing the pad fusion in a state where the tube body 20 is exposed, it is possible to confirm that the tube bodies 20 are appropriately fused to each other. It can be easily confirmed.

  When the butt welding between the pipe ends of the pipe member 12 (specifically, the pipe main body 20) is completed, the butt welding machine 50 is removed as shown in FIG. At this time, since the connection portion of the pipe member 12 is raised on the outer peripheral surface to form the bead 26, as shown in FIG. 4B, the bead 26 is removed using a bead cutter (not shown) or the like, and the pipe member 12 is removed. Is smoothed. In this way, by removing the bead 26 and minimizing the portion that protrudes outward from the outer peripheral surface of the tube main body 20, the protection member 24 described below is less likely to be damaged at the time of construction, and the damage of the tube main body 20 is further reduced. It is reliably prevented.

  Subsequently, as shown in FIG. 4 (C), the above-described drawing is applied to a portion where the protective layer 22 of the connected tube member 12 is peeled off, that is, a portion where the outer peripheral surface of the tube main body 20 is exposed. The protective layer 22 peeled off in the step 3 (B) is wound as a protective member 24. Here, it is costly to separately manufacture the protection member 24 that covers the exposed portion of the tube main body 20, and it is not easy to manufacture the protection member 24 suitable for the exposed portion. Is used as the protection member 24, the manufacturing cost of the protection member 24 can be reduced, and the protection member 24 can be adapted to the exposed portion of the tube main body 20.

  Thereafter, as shown in FIG. 4 (D), the protective member 24 is fixed to the tube member 12 by attaching an adhesive tape 28 to both ends and cut portions of the protective member 24. However, the fixing to the protection member 24 with respect to the pipe member 12 may be performed by welding or bonding. Then, the connection operation between the pipe members 12 is repeated in the same manner until the gas pipe 10 reaches the required length, and when the gas pipe 10 reaches the required length, this manufacturing operation is ended. Since the entire outer peripheral surface of the gas pipe 10 thus manufactured is covered with the protective layer 22 and the protective member 24, the pipe body 20 is appropriately prevented from being damaged at the time of construction.

  Subsequently, referring to FIG. 5, an underground laid pipe updating method for updating an existing gas pipe laid underground by a non-drilling method using the gas pipe 10 prepared as described above as a new pipe. An example will be described. Here, a method of replacing the ductile cast iron pipe 100, which is an existing gas pipe for medium pressure B, with the same diameter will be described.

  As shown in FIG. 5, in this updating method, first, the starting shaft 102 is excavated at one end of the renewal section of the ductile cast iron pipe 100, and the reaching shaft 104 is excavated at the other end. Both ends of the ductile cast iron pipe 100 are opened in the vertical shaft 102 and the reaching vertical shaft 104, respectively.

  In the vicinity of the starting shaft 102 and the reaching shaft 104, various devices, instruments, members, and the like necessary for construction are prepared. For example, the plurality of pipe members 12, the butt fusion machine 50 (see FIG. 3), the cutting and expanding device 112, and the like are carried into the starting shaft 102 side, which is the starting point. On the other hand, a drawing device 118 and a hydraulic unit (not shown) are installed on the end shaft 104, which is the end point.

  A guide roller for guiding the gas pipe 10 smoothly into the ductile cast iron pipe 100 is installed in the starting shaft 102. In this embodiment, the guide rollers include a support roller 106 provided on the upper edge of the starting shaft 102 opposite to the ductile cast iron tube 100, and a holding roller 108 provided in the starting shaft 102. The support roller 106 supports the gas pipe 10 from below, thereby preventing the gas pipe 10 from being damaged by contact with the upper edge portion of the starting shaft 102 and increasing the drawing resistance. The press roller 108 presses the gas pipe 10 from above and allows the gas pipe 10 to be pulled in horizontally with the gas pipe 10 centered on the ductile cast iron pipe 100, so that the edge of the ductile cast iron pipe 100 Suppression of damage to the gas pipe 10 due to contact with a part and stress relaxation at the time of retraction are performed. Here, it is preferable that the installation position of the pressing roller 108 be a position that is about 1 to 2 m away from the edge of the ductile cast iron pipe 100 than near the edge of the ductile cast iron pipe 100. Thereby, the gas pipe 10 is not sharply bent due to the pressing down of the press roller 108, and the gas pipe 10 can be guided more smoothly in the ductile cast iron pipe 100. This is because it is possible to reduce the size of.

  When the preparation for construction is completed, next, on the ground on the starting shaft 102 side, the plurality of pipe members 12 are butt-fused to each other by the above-described method shown in FIGS. Is prepared.

  After the gas pipe 10 having the required length is manufactured, the gas pipe 10 is inserted into the ductile cast iron pipe 100. In this embodiment, the gas pipe 10 is drawn into the ductile cast iron pipe 100 while cutting and ductile the ductile cast iron pipe 100 in the axial direction using the cutting and expanding device 112. As the cutting and expanding device 112, a known device may be appropriately used. For example, the cutting and expanding device 112 includes a blade 114 having a plurality of disk-shaped cutter bodies, and an expander 116 formed in a bullet shape. The outer diameter of the expander 116 may be set to a size that allows the ductile cast iron tube 100 to expand as large as possible within a range that does not destroy the ductile cast iron tube 100. If the ductile cast iron pipe 100 is broken, the gas pipe 10 is adversely affected, and if the ductile cast iron pipe 100 is too small in diameter, the outer peripheral surface of the gas pipe 10 is easily damaged. It is.

  When drawing the gas pipe 10 into the ductile cast iron pipe 100, first, a rod is inserted into the ductile cast iron pipe 100, and the end of the rod 110 on the reaching shaft 104 side is connected to the drawing apparatus 118. On the other hand, a cutting and expanding device 112 is connected to the end of the rod 110 on the starting shaft 102 side, and the tip of the gas pipe 10 is connected to the cutting and expanding device 112. The gas pipe 10 is disposed so as to pass through the support roller 106 and the press roller 108. Then, the retracting device 118 is driven to pull the rod 110 toward the reaching shaft 104, thereby moving the cutting and expanding device 112 toward the reaching shaft 104 and cutting and expanding the ductile cast iron tube 100. The gas pipe 10 is drawn inside. At this time, since the entire outer peripheral surface of the gas pipe 10 is covered with the protective layer 22 and the protective member 24, only the protective layer 22 and the protective member 24 are damaged by contact with the ductile cast iron pipe 100. The damage to the main body 20 is appropriately prevented.

When the gas pipe 10 is inserted over the entire length of the renewal section of the ductile cast iron pipe 100, this replacement work is completed. In addition, since the ductile cast iron pipe 100 is left so as to cover the periphery of the gas pipe 10, the gas pipe 10 is protected from other works after the construction.

As described above, according to this embodiment, it is possible to manufacture the gas pipe 10 in which the pipe bodies 20 are appropriately welded to each other and the pipe body 20 can be prevented from being damaged during construction. Therefore, the gas pipe formed by using this gas pipe 10 can maintain the durability against the gas pressure (internal pressure) for a long period of time, and the construction quality is improved and stabilized.

  In particular, since the gas pipe 10 can appropriately prevent the pipe body 20 from being damaged by the protective layer 22, the outer peripheral surface of the new pipe is easily damaged at the time of construction, and can be suitably used for replacing the existing gas pipe with the same diameter. . In addition, in order to improve and stabilize the construction quality, the gas pipe 10 can be suitably used not only for a low-pressure pipe (gas pressure is less than 0.1 MPa) but also for a medium-pressure B pipe.

  In the above-described embodiment, the work of peeling off the protective layer 22 at the end of the pipe member 12 is performed at the construction site. However, this work is performed at another place such as a factory, and the protective layer 22 at the end is formed. The peeled pipe member 12 and the removed protective layer 22 (protective member 24) may be individually carried into the construction site. Further, it is not always necessary to use the removed protective layer 22 as the protective member 24, and a separately prepared protective member 24 can be used.

  Further, in the above-described embodiment, the beads 26 generated at the time of bad fusion are removed, but the beads 26 need not necessarily be removed. When the bead 26 is not removed, the entire exposed portion of the tube body 20 including the bead 26 may be covered with the protection member 24, or the protection member 24 may be attached so that the bead 26 is exposed. Is also good. Further, in the above-described embodiment, the ductile cast iron pipe 100 is replaced with the same diameter by using the gas pipe 10, but the existing gas pipe updated by the gas pipe 10 is a gray cast iron pipe and a steel pipe. You may. The existing gas pipe updated by the gas pipe 10 may have a larger diameter or a smaller diameter than the gas pipe 10. Further, the gas pipe 10 can be used not only for renewing an existing gas pipe, but also for burying a new gas pipe in a place where there is no existing gas pipe by a non-cutting method.

  Furthermore, in the above-described embodiment, the gas pipe is exemplified as the pipe for the non-cutting new pipe laying method. However, the pipe for the non-cutting new pipe laying method (underground pipe) in the manufacturing method or the updating method according to the present invention. Is not limited to gas, but may be used for transporting other fluids such as water, pressure sewage, and fire extinguishing.

  Note that the specific numerical values such as the dimensions described above are merely examples, and can be appropriately changed as needed.

10… Pipe for gas (Pipe for non-cutting new pipe laying method, new pipe)
20 ... pipe body 22 ... protective layer 24 ... protective member 100 ... ductile cast iron pipe (existing pipe)
112… Cutting expander

Claims (6)

A method for producing a pipe for a non-drilling new pipe laying method laid underground by a non-drilling method,
(A) a step of preparing a plurality of pipe members having a protective layer on the outer peripheral surface of a pipe body made of a polyolefin resin;
(B) peeling off the protective layer at the end of the tube member;
(C) connecting the pipe ends of the pipe members from which the protective layer has been peeled off in the step (B) by butt fusion; and (D) protecting the pipe members connected in the step (C). A method for producing a pipe for a non-drilling new pipe laying method, comprising a step of attaching a protective member to a portion from which a layer has been removed.   2. The method of claim 1, wherein in the step (D), the protection layer peeled off in the step (B) is used as the protection member. 3.   3. The method of laying a new pipe according to claim 1, further comprising: (E) removing a bead generated by the butt fusion after the step (C) and before the step (D). 4. Method for manufacturing piping for An underground pipe replacement method for replacing an existing pipe laid underground with a new synthetic resin pipe by a non-cutting method,
(A) preparing a plurality of pipe members having a protective layer on the outer peripheral surface of a pipe body made of a polyolefin resin;
(B) peeling off the protective layer at the end of the tube member;
(C) connecting the pipe ends of the pipe members from which the protective layer has been peeled off in the step (b) by butt fusion;
(D) attaching the protective member to the portion of the tube member connected in the step (c) from which the protective layer has been peeled off to produce the new pipe; and (e) attaching the new pipe to the pipe member. A method for updating an underground pipe, comprising inserting the pipe into an existing pipe.   The underground pipe updating method according to claim 4, wherein in the step (d), the protection layer peeled off in the step (b) is used as the protection member. The new pipe is a pipe having the same diameter as the existing pipe,
The underground laying according to claim 4 or 5, wherein, in the step (e), the new pipe is inserted into the existing pipe while cutting and expanding the existing pipe in an axial direction using a cutting and expanding device. How to update the tube.

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