JP2013094751A - Method of forming resin lining on inner surface of existing pipe and jig for resin lining - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of forming a resin lining to the inner surface of an existing pipe using a pig, capable of depositing a film having a uniform thickness in the circumferential direction of the resin lining film in spite of a simple method.SOLUTION: The method is for forming the resin lining film corresponding to a gap between an outer periphery of a pig and the inner surface of the pipe by using the pig having the diameter which is smaller than the internal diameter of the pipe, filling with the resin disposed forwardly of traveling direction of the pig inserted in the pipe to form the resin reservoir and move the pig by pressing the resin reservoir. The specific gravity of the pig is 0.3 to 0.7.

Description

  The present invention relates to a resin lining method for an inner surface of an existing pipe and a resin lining jig.

  For old pipes that have deteriorated, a method of repairing airtightness by forming a resin lining film on the inner surface has been known for a long time, and many methods have been proposed according to the site conditions. .

  The prior art described in Patent Document 1 below is a method using a spherical pig having a slightly smaller diameter than the inner diameter of the tube. According to this, a resin reservoir is formed by filling the front of the pig inserted in the pipe in the direction of travel, and the pig is moved along the pipe so as to push the resin reservoir. A resin lining film is formed between the two.

JP-A-8-24758

  In the resin lining method using such a pig, it is difficult to move the pig in a state where the center of the pig is aligned with the center of the pipe. At this time, if the center of the pig is shifted upward with respect to the center of the tube, the film thickness of the resin lining film becomes thinner at the top and thicker at the bottom. Conversely, when the center of the pig is shifted downward with respect to the center of the tube, the thickness of the resin lining film becomes thicker on the upper side and thinner on the lower side.

  Thus, when the film thickness of the resin lining film becomes non-uniform in the circumferential direction, the film thickness of the thinned portion may not reach the set film thickness, which causes a problem that the pipe cannot be sufficiently repaired. Conventionally, in order to avoid this, by increasing the difference between the outer diameter of the pig and the inner diameter of the pipe to increase the overall film thickness, even the thinnest film thickness is greater than the set film thickness. Such construction was done. However, in such construction, there is a problem that the effective diameter in the pipe is narrowed by increasing the thickness of the resin lining film more than necessary, and the construction cost is increased because a large amount of resin is used. It was.

  On the other hand, there are various laying states of existing pipes to be constructed, and in a state where both ends are open in a relatively short pipe state, a construction method capable of keeping construction costs as low as possible with a simple construction method is required. . For example, taking gas piping as an example, the supply pipe branched from the main branch below the road passes through the boundary wall between the road and private land (residential land) and the wall of the reinforced structure along the road, and pipes into the private land and building. May be. In such a state where existing pipes are laid, when the gas company performs replacement work between the main pipe and the supply pipe, if it is difficult to replace the pipe that penetrates the wall, it passes through the wall. The pipe is partially left in the state, and the remaining wall penetration pipe is a straight short pipe of about 2 m. In order to form a resin lining film on such a wall through pipe, it is necessary to perform construction from the outside of the wall, and simple and low cost construction is required.

  This invention makes it an example of a subject to cope with such a problem. That is, in the resin lining method of the existing pipe inner surface using a pig, the circumferential film thickness of the resin lining film can be uniformly applied while being simple construction, and the circumferential film thickness of the resin lining film is uniform. Therefore, it is possible to avoid the need to increase the film thickness more than necessary, to minimize the amount of resin used and to perform low-cost construction, and to provide a resin lining method suitable for the construction of wall through pipes. It is an object of the present invention to be able to do so.

In order to achieve such an object, the resin lining method for the existing pipe inner surface according to the present invention has at least the following configuration.
A pig having a diameter smaller than the inner diameter of the pipe is used, and a resin reservoir is formed by filling resin in the forward direction of the pig inserted in the pipe, and the pig is pushed along the pipe so as to push the resin reservoir. Is a method of forming a resin lining film on the inner surface of the pipe according to the gap between the outer periphery of the pig and the inner surface of the pipe, wherein the specific gravity of the pig is 0.3 to 0.7. The resin lining method for the inner surface of existing pipes.

  By appropriately setting the specific gravity of the pig, the position of the pig can be held at the center of the pipe when the resin lining film is formed on the inner surface of the pipe while pushing and moving the resin reservoir. The specific gravity of the resin used for the resin lining is in the range of about 1.1 to 1.2. By making the specific gravity of the pig 0.3 to 0.7, the pig floats or sinks in the resin pool. You can move without having to. Thereby, a resin lining film uniform in the circumferential direction can be formed on the inner surface of the pipe.

  Since a uniform resin lining film can be formed in the circumferential direction, it is possible to perform construction with a minimum amount of resin necessary for ensuring airtightness, thereby enabling low-cost construction.

It is explanatory drawing which showed an example of the piping state which can apply the resin lining construction method which concerns on embodiment of this invention. It is explanatory drawing which showed each process of the resin lining construction method which concerns on one Embodiment of this invention. This is a graph showing the experimental investigation of the thickness of the resin lining film at the upper position (12 o'clock position) and the lower position (6 o'clock position) of the pipe cross section when the specific gravity of the pig is changed. is there. This is a graph showing the experimental investigation of the thickness of the resin lining film at the upper position (12 o'clock position) and the lower position (6 o'clock position) of the pipe cross section when the specific gravity of the pig is changed. is there. It is the correlation graph which calculated | required the average value of the film thickness of a 12:00 position, and the film thickness of a 6 o'clock position for every specific gravity of a pig, made the difference the vertical axis | shaft, and made the horizontal axis the specific gravity of a pig.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view showing an example of a piping state to which the resin lining method according to the embodiment of the present invention can be applied. Here, the gas conduit will be described as an example, but the present invention is not particularly limited thereto.

  As shown in FIG. 1A, most of the branch pipe P1 in the gas conduit is laid under the road. In order to draw the supply pipe P2 branched from the main branch pipe P1 into the inside of the reinforcing bar building M and connect it to the internal gas equipment m1, the supply pipe P2 is drawn through the building base wall (reinforcing bar wall), and the gas meter ( (Not shown) and connected to the gas device m1 through the gas plug m2. In such a piping state, the main branch pipe P1 buried under the road and the supply pipe P2 to the outside of the wall of the reinforcing bar building M are assets of the gas company, and the piping in the reinforcing bar building M (in the premises) is in demand. Become a home asset.

  When the gas company performs the replacement work of the main pipe P1 and the supply pipe P2, as described above, as shown in FIG. Has been done to leave. Maintenance of the remaining wall through pipe P is performed by a gas company. When resin lining is applied to the wall through pipe P, it is necessary to perform work from the outside of the wall Ma.

  Drawing 2 is an explanatory view showing each process of a resin lining construction method concerning one embodiment of the present invention. In the embodiment of the present invention, a pig having a diameter smaller than the inner diameter of the pipe is used, and a resin reservoir is formed by filling the resin forward in the traveling direction of the pig inserted into the pipe, and the resin reservoir is pushed. The premise is a method of forming a resin lining film on the inner surface of the pipe according to the gap between the outer periphery of the pig and the inner surface of the pipe by moving the pig along the pipe. The movement of the pig at this time may be movement by any means as long as the movement is not largely restricted in the weight direction. In the following description, an example of a construction method for the above-described wall penetration pipe P will be described, but the present invention is not particularly limited thereto.

  The wall through pipe P is a straight pipe having both ends open, and a resin lining film is formed on the inner surface of the pipe by working from one side of the pipe end. For this purpose, the pig 1 with the traction string 1a and the pig 2 with the hand bar 2a are used as a resin lining jig. The tip of the pulling string 1a is connected to the center of the pig 1 and the tip of the hand bar 2a is connected to the center of the pig 2. Both the pig 1 and the pig 2 have a spherical shape having a diameter smaller than the inner diameter of the wall penetration pipe P, and the diameter of the pig 2 is the same or slightly larger than the diameter of the pig 1.

  In the process shown in FIG. 2A, the pig 1 with the traction string 1a is inserted from one end side of the wall through pipe P toward the other end side. At this time, the introduction joint 3 is attached to one end of the wall through pipe P, and the pig 1 is inserted into the pipe from one end of the wall through pipe P. Thereafter, the pig 2 with the hand bar 2a is inserted into the pipe from one end of the wall through pipe P, and the hand bar 2a is pushed toward the other end of the wall through pipe P to push the pig 1 to the other end of the wall through pipe P. Move to the side. The introduction joint 3 is provided with a resin injection port 3a.

  In the step shown in FIG. 2 (b), the pig 2 with the push bar 2a is once pulled out to one end side, and as shown in FIG. 2 (c), it passes from the one end side of the wall through pipe P into the pipe through the resin injection port 3a. Resin 4 is filled. Thereafter, as shown in FIG. 2 (d), the resin reservoir 4 a is sent to the front of the pig 1 by moving the pig 2 with the push bar 2 a from the one end side of the wall through pipe P toward the other end side. At this time, a primary lining film is formed on the inner surface of the pipe by the movement of the pig 2.

  In the step shown in FIG. 2 (e), the pig 2 with the push bar 2a is pulled out to one end side of the wall through pipe P, and then the tow string 1a is pulled from one end side of the wall through pipe P, thereby The wall penetrating pipe P is moved from the other end side toward the one end side. As a result, a secondary lining film is formed on the previously formed primary lining film, and a resin lining film 5 having a set thickness is also formed.

  In the resin lining method having such a process, the film thickness of the resin lining film 5 can be made uniform in the circumferential direction by appropriately setting the specific gravity of the pig 1. As shown in FIG. 2 (e), when the pig 1 is pulled by the tow string 1a, the pig 1 moves in the resin reservoir 4a without restriction in the direction of gravity. Directional behavior changes. If the pig 1 is too light, the pig 1 is likely to rise due to buoyancy generated during movement, and the film thickness of the resin lining film 5 becomes thin at the upper position of the pipe cross section (position at 12 o'clock). Accordingly, the resin lining film 5 becomes thicker at the lower position of the pipe cross section (the position of the clock hand at 6 o'clock). On the other hand, when the pig 1 is too heavy, the pig 1 is likely to sink while moving due to gravity, and the film thickness of the resin lining film 5 at the lower position of the pipe cross section (6 o'clock position of the clock hand) is Accordingly, the thickness of the resin lining film 5 is increased at the upper position of the tube cross section (the position of the clock hand at 12 o'clock).

  In the embodiment of the present invention, paying attention to the behavior of the pig 1 in the resin reservoir 4a as described above, the thickness of the resin lining film 5 is made uniform in the circumferential direction by setting the specific gravity of the pig 1 appropriately. To do. The resin such as an epoxy resin used for the resin lining is not greatly different in the specific gravity range of 1.1 to 1.2 regardless of the resin. Therefore, by setting the specific gravity of the pig 1 to an appropriate value obtained experimentally, it is possible to obtain an effect of improving the uniformity of the resin lining film in a generally performed resin lining method.

  3 and 4 show that when the specific gravity of the pig is changed, what is the thickness of the resin lining film at the upper position (12 o'clock position) and the lower position (6 o'clock position) of the pipe cross section. It is the graph which carried out experiment investigation. Here, the construction method shown in FIG. 2 is adopted, and a pipe having a diameter of 80A is targeted. The resin used is an epoxy resin with a specific gravity of 1.15. A resin lining film 5 is formed in the steps of FIGS. 2 (a) to 2 (e) using a pig 1 having a specific gravity different from 0.2, 0.41, 0.55, 0.64, and 1.04. The film thickness (mm) of the resin lining film 5 was measured at the upper position (12 o'clock position) and the lower position (6 o'clock position) at positions 10 cm, 30 cm, and 50 cm from the edge. The value of each point in the graph is an average value of a plurality of measured values.

  FIG. 5 shows the average value of the film thickness at 12 o'clock and the film thickness at 6 o'clock for each specific gravity of Pig 1 based on the measurement results of FIGS. It is the correlation graph which made the horizontal axis the specific gravity of Pig1. As is apparent from this graph, the film thickness difference between the 12 o'clock position and the 6 o'clock position can be minimized by appropriately setting the specific gravity of the pig 1. And by making the specific gravity of the pig 1 between 0.4 and 0.6, the film thickness difference between the 12 o'clock position and the 6 o'clock position can be minimized. Further, by making the specific gravity of Pig 1 0.3 to 0.7, it is possible to suppress the difference in film thickness within an allowable range in which there is no practical problem.

  The specific gravity of the pig 1 can be adjusted by various methods. For example, a pig is molded with a single foam sponge or the like having a relatively low specific gravity, and a weight for adjusting the specific gravity is built in the center of the pig at the time of molding, or a pig is made with a polymer material or metal material with a relatively high specific gravity. There is a method in which the specific gravity is adjusted by the size of the cavities formed and the cavities formed therein. The material of the pig 1 is an important factor in setting the specific gravity, but is not limited to a specific material.

  The specific gravity of the pig 1 is set in the range of 0.3 to 0.7, and the resin lining film 5 is formed on the wall through pipe P in the process shown in FIG. While being applied, the resin lining film 5 having a substantially uniform thickness in the circumferential direction can be formed. Further, by making the film thickness in the circumferential direction of the resin lining film 5 uniform, it is possible to avoid making the film thickness unnecessarily thick and to perform the low-cost construction by minimizing the amount of resin used. Thereby, it is possible to provide a resin lining method particularly suitable for the construction of the wall through pipe P.

1: Pig, 1a: Tow string,
2: Pig, 2a: Hand bar
3: Introduction joint, 3a: Resin injection port,
4: Resin, 4a: Resin pool,
5: Resin lining film,
P: Wall through pipe, P1: Main branch pipe, P2: Supply pipe,
M: Reinforcement building, Ma: Wall

Claims (4)

A pig having a diameter smaller than the inner diameter of the pipe is used, and a resin reservoir is formed by filling resin in the forward direction of the pig inserted in the pipe, and the pig is pushed along the pipe so as to push the resin reservoir. Is a method of forming a resin lining film on the inner surface of the pipe according to the gap between the outer periphery of the pig and the inner surface of the pipe,
A resin lining method for the inner surface of an existing pipe, wherein the specific gravity of the pig is 0.3 to 0.7.   2. The resin lining method for the inner surface of an existing pipe according to claim 1, wherein the specific gravity of the pig is 0.4 to 0.6. Inserting the pig with a traction string from one end side of the tube toward the other end side;
Filling the tube with resin from one end side of the tube, and moving the pig with a push rod from the one end side to the other end side of the tube, and sending the resin reservoir to the front of the pig; and
After pulling out the pig with the push bar to one end side of the tube, the step of moving the pig from the other end side of the tube toward the one end side by pulling a tow string from the one end side of the tube. 3. A resin lining method for the inner surface of an existing pipe according to claim 1 or 2.   It is a jig | tool used for the resin lining construction method described in Claim 3, Comprising: The resin lining jig | tool which consists of the said pig with a hand bar and the said pig.

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