JPS6124066B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of the Invention The present invention relates to a pipe lining method for repairing, reinforcing, etc. the pipe by applying a lining film to the inner surface of the pipe such as a gas main pipe.

(2) Conventional technology and its problems For example, when a leak occurs in a supply pipe that supplies gas from a low-pressure city gas main to a building or other building and requires repair, conventionally a leak occurs. Although efforts are being made to dig up and replace the pipes, it is necessary to replace the pipes over a fairly long area.
It's a big job. Moreover, even during repair work, the gas supply to the low-pressure mains cannot be shut off.
Repair work for gas supply pipes is extremely difficult work, requiring a great deal of labor and cost.

(3) Purpose of the Invention The present invention has been made based on the above circumstances, and its purpose is to provide a simple gas supply system by forming a lining layer on the inner surface of a buried gas supply pipe or an existing pipe installed in a building, etc. It is an object of the present invention to provide a lining device for the inner surface of a tube, which can repair or reinforce the inner surface of the tube with a simple operation.

(4) Structure of the Invention The present invention is applied to the case where a lining film is formed on the inner surface of a gas supply pipe branching from a gas main pipe.

The present invention includes a step of force-feeding a pressing body equipped with a pulling member from an opening at one end of the gas supply pipe to be lined toward the gas main pipe using gas at a higher pressure than the gas pressure of the gas main pipe. , a step of injecting a lining agent into the gas supply pipe after force-feeding the pressing body to the gas main pipe side; and applying a lining agent to the inner surface of the gas supply pipe.

(5) Embodiment of the Invention An embodiment of the method of the present invention is shown below in Figures 1 to 3.
This will be explained with reference to the figures. In the figure, reference numeral 1 denotes a gas supply pipe as an example of a pipe that requires repair, and an opening 1a at one end of the gas supply pipe 1 is connected to a gas meter at a demand end such as a building. Also,
The other end opening 1b of the gas supply pipe 1 is connected to a branch pipe 2a of a low-pressure main pipe 2 for city gas or the like. 3 is a pressing body used when lining the tube 1 mentioned above. This pressing body 3 is a disk-shaped impregnating member that can be impregnated with liquid, such as a sponge, and has pressing plates 4,
5, and a traction member 6 such as a wire rope is connected thereto.

The repair and reinforcement work for the gas supply pipe 1 is carried out as follows. First, the opening 1a at one end of the gas supply pipe 1, that is, the part of the meter on the building side is removed, and the pressing body 3 and the pulling member 6 are inserted through this opening 1a. Then, pressurized gas is forced into the tube 1 from the opening 1a side, and the pressure causes the pressing body 3 to be forced towards the opening 1b on the other end side, as shown in FIG. This pressurized gas is of the same composition as the demand gas such as city gas flowing through the low-pressure main pipe 2, and is fed into the pipe 1 at a pressure higher than the gas pressure within the low-pressure main pipe 2. In addition, in order to reduce the friction between the pressing body 3 and the inner surface of the pipe 1, the pressing body 3 may be impregnated with a lubricant in advance, or the pressing body 3 may be impregnated with a lining agent 7, which will be described later, in advance. Accordingly, this lining agent may function as a lubricant.

Then, as shown in FIG. 2, when the pressing body 3 reaches the branch pipe part 2a of the low-pressure main pipe 2 and exits to the low-pressure main pipe 2 side, the pressure inside the pipe 1 decreases, so that it reaches the low-pressure main pipe 2. You can know what you did.

Next, the pulling member 6 is pulled slightly to return the pressing body 3 to the inside of the pipe 1, and by blocking the inside of the pipe 1 with the pressing body 3, the demand gas flowing inside the low-pressure main pipe 2 is directed to the pipe 1 side. Prevent it from flowing.

Then, the lining agent 7 is applied from the outside of the tube 1 into the tube 1.
is injected to impregnate the pressing body 3. As the lining agent 7, for example, an epoxy resin or a urethane resin in the form of medium to high viscosity liquid, or a foamed resin using a foaming agent is used.

Then, the pulling member 6 is pulled toward the opening 1a to move the pressing body 3. As a result, the lining agent 7 impregnated in the pressing body 3 oozes out, and since the pressing body 3 is pressed against the inner surface of the pipe 1, as the pressing body 3 moves, the outer peripheral portion 3a of the pressing body 3
The lining agent 7 is applied to the inner surface of the tube 1.
Further, the excess lining agent 7 is pushed by the pressing body 3 as the pressing body 3 moves and moves toward the opening 1a side. Therefore, a lining film 7a is formed on the inner surface of the tube 1 after the pressing body 3 passes therethrough. Then, by curing after a predetermined period of time, it is fixed as a lining layer.

According to the above method, repair and reinforcement can be carried out from inside the pipe without digging up an existing pipe such as a buried gas supply pipe or removing the pipe installed in a building or the like. In addition, in the past, the parts that required repair were cut and replaced with new pipes, which made the work large-scale and took a long time. Since the pipe can be directly repaired from the inside, complex piping can be easily repaired.

Furthermore, during the lining work, the pressing body 3 can shut off the required gas in the low-pressure main pipe 2, so that gas leakage can be prevented during the lining work.

Since the lining agent 7 is applied to the inner surface of the tube 1 by the pressing body 3, cracks, pinholes, etc. that occur in the tube 1 can be reliably filled with the lining agent, and the lining coating 7 has a uniform thickness.
A can be formed. Then, the excess lining agent 7 is pushed to the opening 1a as the pressing body 3 is pulled.
Since the lining agent that moves to the side and is ultimately left over can be collected through the opening 1a, the lining agent 7 is not wasted and is economical.

Note that FIGS. 4 and 5 show a modified example of the pressing body 3, and this pressing body 3 is made by superimposing an impregnated member 11 such as a sponge on a base plate 10 made of an elastic material such as rubber. Both the base plate 10 and the impregnated member 11 have a shade shape. The traction member 6 is connected by a stopper 12. This pressing body 3 is fed by gas pressure toward the opening 1b on the other end side of the tube 1, as in the above-mentioned embodiment, and during pressure feeding, the pressing body 3 is moved as shown in FIG. The outer circumferential portion 3a falls toward the rear 3 side in the feeding direction, that is, toward the traction member 6 side, so that it becomes tapered and moves forward within the tube 1, so that it can move smoothly within the tube 1. On the other hand, when pulling the pulling member 6 to move the pressing body 3 toward the opening 1a,
As shown in FIG. 5, the outer peripheral portion 3a of the pressing body 3 is reversed to the rear 3 side in the pulling direction, that is, to the opposite side of the pulling member 6. Therefore, when the pressing body 3 is pulled, its outer peripheral portion 3a is elastically reduced in diameter, and an annular gap 13 of an appropriate width is formed between it and the inner surface of the tube 1. This is effective in forming the lining film 7a with a large uniform thickness.

Further, FIG. 6 shows another modification of the pressing body 3, and this pressing body 3 is constructed by stacking a plurality of impregnated members 14, such as sponges, in the axial direction. Therefore, it is possible to impregnate a large amount of lining agent.

(6) Effects of the Invention As explained above, the present invention moves the pressing body equipped with a pulling member from the opening at one end of the gas supply pipe to be lined toward the gas main pipe to lower the gas pressure of the gas main pipe. In addition to being pumped with high-pressure gas,
After the pressing body is force-fed to the gas main pipe side, a lining agent is injected into the gas supply pipe, and while the pressing body is pulled toward the opening side using the pulling member, the lining agent is applied to the outer periphery of the pressing body. is applied to the inner surface of the gas supply pipe.

Therefore, according to the present invention, the lining inside the gas supply pipe can be performed only through the opening at one end of the gas supply pipe without stopping the gas flowing inside the gas main pipe. In addition, the excess lining agent injected into the pipe moves with the pressing body as the pressing body is towed and moves, and can be collected at the opening of the pipe, so the lining agent is not wasted and is economical. It is true.

Moreover, since the inside of the pipe can be shut off by the pressing body, it is not necessary to repair the gas supply pipe while the gas is flowing, for example when repairing a gas supply pipe connected to the main pipe of city gas etc. It also has the effect of preventing gas from escaping during lining work in some cases.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views showing an embodiment of the method of the present invention in the order of steps, FIGS. 4 and 5 are cross-sectional views showing a modified example of the pressing body in different operating states, and FIG. The figure is a sectional view showing another modification of the pressing body. 1...Pipe, 1a...Opening on one end side, 1b...Opening on the other end side, 2...Low pressure main pipe (gas main pipe), 3...
...Pushing body, 3a... Outer peripheral part, 6... Traction member,
7...Lining agent, 7a...Lining film.

Claims (1)

[Claims] 1. A method for forming a lining film on the inner surface of a gas supply pipe branching from a gas main pipe, the method comprising: pulling the gas supply pipe to be lined from an opening at one end toward the gas main pipe; a step of force-feeding a pressing body provided with the member with gas at a higher pressure than the gas pressure of the gas main; and a step of injecting a lining agent into the gas supply pipe after the pressing body is force-fed to the gas main side. , a step of applying the lining agent to the inner surface of the gas supply pipe at the outer periphery of the pressing body while pulling the pressing body toward the opening side by the pulling member. Lining method.