JPH0133718B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for ensuring sealing performance from the inner surface of the pipe while the pipe joint part of an existing gas pipe is mainly buried underground. This invention relates to a pipe joint repair device for an existing pipe to be repaired.

[Conventional technology]

In recent years, various methods have been proposed for repairing existing pipes such as gas pipes, water pipes, etc. buried underground from the inside so as to regenerate the pipes from corrosion and the like while they are still buried. In particular, with existing gas pipes buried underground, where cast iron pipes are connected using water-type joints or G-type joints, the sealing performance of the pipe joints has deteriorated and there is a need for repair. .
In other words, recently, city gas has become dry natural gas instead of the coal gas that had been used for a long time. The deterioration of sealing properties occurs because it penetrates into the sealing material called "hemp skin".
There was no particular problem.

However, in the case of dry natural gas, the above sealing material dries and contracts, creating voids.
Since the sealing performance deteriorates and causes gas leakage, we will ensure the sealing performance of the pipe joint, and from now on,
There is a need to carry out repairs that will not cause seal deterioration.

However, for existing gas pipes with medium or small diameters, workers cannot enter the pipes and repair the inner surface of the pipe joints like they can with large-diameter pipes, so repair work is difficult. This is difficult, and there is a need for a construction method in which a worker is on the outside and repairs the joints of the pipes from the inside while they are buried.

Regarding this construction method, the present inventor has a means for filling and moving resin between at least a pair of front and rear pigs that slide into and in airtight contact with the inner surface of the pipe in the existing pipe, and in this moving process, When the pipe fitting is located between the front and rear pigs, in the first step, a low-viscosity resin penetrant is impregnated into the sealing material from between the pipe fittings under pressure, and in the second step, the sealing material is impregnated from between the pipe fittings. We have developed a repair method that involves filling the area with a high-viscosity resin putty. According to this repair method, not only is it possible for an operator to repair the joint part of the pipe from the inside while it is buried while the worker is outside, but also the penetrating agent that is pressurized and impregnated into the sealing material can dry the sealing material. The sealing effect is enhanced by closing the micropores caused by shrinkage, and the penetrating agent from the gap in the first stage acts as a lubricant for the filling of the putty agent in the second stage. , Between the pipe joints Even if the surface is rough and uneven, the putty fills with good adhesion, and the double airtightness of the penetrant and putty allows for highly effective repairs. .

[Problem to be solved by the invention]

The present invention is directed to a repair device used for carrying out the above-mentioned repair method, which has the drawback that when the pig is moved, resin may enter a branch pipe branched from an existing pipe and block the branch opening of the branch pipe. In view of this, it is an object of the present invention to provide an improved pipe joint repair device for existing pipes in order to eliminate this inconvenience.

[Means to solve the problem]

In order to achieve this object, the present invention is provided with a means for filling and moving a resin between at least a pair of front and rear pigs that slide in airtight contact with the inner surface of the pipe in an existing pipe, and move the pig. When the pipe joint of an existing pipe is located between the front and rear pigs during the process, filling pressure is applied to the resin to repair the pipe joint.
A vacuum chamber is formed on the rear side in the direction of movement of the pair of front and rear pigs, which communicates through a communication path with a negative pressure supply source of the required pressure and an opening/closing mechanism, and also detects the branch opening of a branch pipe branching from the existing pipe. a sensor configured to open the opening/closing mechanism to supply negative pressure from the negative pressure source to the vacuum chamber when the branch opening is in a position facing the vacuum chamber when the pig moves. It is characterized by:

[Effect]

When repairing the pipe joint by passing the resin between the front and rear pair of pigs into the existing pipe, a sensor detects when the pig is moving that the branch opening of the branch pipe branching from the existing pipe is on the rear side in the direction of movement of the front and rear pair of pigs. When the position facing the vacuum chamber is detected, a detection signal opens the opening/closing mechanism of the communication path from the negative pressure supply source of the required pressure to supply the negative pressure to the vacuum chamber, and when the pipe joint is repaired. To eliminate the inconvenience that a branch opening of a branch pipe is blocked by sucking out resin flowing into a branch pipe into a vacuum chamber.

〔Example〕

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings.

In the figure, numerals 1, 2, and 3 are cylindrical pigs constituting a triple pig, and a front pig 1, an intermediate pig 2, and a rear pig 3 are each connected to each other via a narrow diameter portion. Above front pig 1 and middle pig 2
A cylindrical flexible bag 4 is disposed at the center between the two pigs so as to straddle both pigs, and an inflatable space 6 is formed inside the flexible bag 4. The flexible bag 4 is an airtight bag made of rubber or resin, and can maintain airtightness itself. The front pig 1 is also formed with an air supply hole 7 that penetrates into the bag 4 from the front, so that pressurized air can be supplied into the space 6 from the front of the front pig 1 via a hose 5. ing.
The pigs 1, 2, and 3 are penetrated by tow ropes that also serve as length measurements and extend in the front-rear direction, and the tow rope 8 that extends forward is connected to the front pig 1, and the tow rope 9 that extends rearward is connected to the rear pig 3. It has been done. Further, on the outer periphery of the front pig 1, there are a suction groove 10 that opens on the tip side and a filling groove 11 that opens on the rear side.
They are formed so as to overlap with each other in the axial direction, and at different positions in the circumferential direction.

Here, a vacuum chamber 22 is formed between the intermediate pig 2 and the rear pig 3. This vacuum chamber 22 is communicated with a negative pressure supply source 24 via a hose 23 passing through the rear pig 3 (see FIG. 2).
An opening/closing mechanism (not shown) is provided on the communication path to interrupt the supply of negative pressure. A sensor 26 for operating this opening/closing mechanism is placed facing the outer periphery of the intermediate pig 2, detects the branch opening of the branch pipe 25 attached to the existing pipe 12, and sends a detection signal to the vacuum chamber. Negative pressure is supplied to 22. In this embodiment, the pigs 1, 2, and 3 are integrally connected to each other at the center.
Although it is in the form of a series of pigs, these pigs 1,
2 and 3 can be configured in a split configuration and connected to each other with a rope.

The repair device having such a configuration is used in the following manner for repairing the inner surface of the existing pipe 12. Here, as shown in Figure 2, the existing pipe 12 buried underground
In the conventional piping system, cast iron pipes are connected via pipe joints 13 and 14 of water type or the like. Pipe joint parts 13, 1 of this existing pipe 12
4, in the present invention, the existing pipe 12 is divided into units of length suitable for repair, and a plurality of pipe joints 13 and 14 interposed within that section are repaired, and the pipe joints 13 are , as is conventionally known,
For example, a large diameter portion 13 provided at the end of one pipe.
a, the other tube end 13b abuts against each other, the butt-fitting part is filled with a sealing material 15 usually called "hemp skin", and the opening is sealed with a lead material 16. It is of structure.

The pigs 1, 2, and 3 are introduced into the existing pipe 12 to be repaired through one opening.
In the present invention, a hardenable low-viscosity resin (10 cps to 1000 cps) such as an epoxy resin is infiltrated into the opposing space between the front pig 1 and the intermediate pig 2 (excluding the space occupied by the bag 4). Agent A,
Or high viscosity resin (e.g. 10,000 cps to 300,000 cps)
The putty agent B is filled and moved inside the existing pipe 12 by being pulled by the towing rope 8.

In the first stage, as seen in FIGS. 1 and 2, the space between the pigs 1 and 2 is filled with penetrant A, which is moved in the direction of the arrow X. In this movement, the pigs 1 to 3 are moved together with the penetrant A by the pulling rope 8 while applying a predetermined negative pressure (for example, -0.5 kg/cm ² ) inside the existing pipe 12 on the front side in the moving direction. During this movement process, judging from the piping diagram and pulling out (length measurement) of the towing rope 8, or by installing a video camera or magnetic sensor 18 on the towing rope 8,
This confirms the position of the pipe joint part 13 or 14, and based on that determination, the front pig 1 connects the pipe joint part 1.
When the pig moves to position 3 (or 14), the movement of the pig is temporarily stopped or at a low speed at this position, and pressurized air is supplied into the bag 4 through the air supply hole 7 in this state. As a result, the expansion of the bag 4 applies pressure in the direction of arrow Z, and filling pressure is applied to the penetrating agent A. As a result, the penetrant A is pumped through the groove 11 of the pig 1 to the pipe joint 13,
It penetrates into the sealing material 15 through the space 19 between the pipe joints 13.

At this time, if there is an air leak in the pipe joint 13 (or 14), the penetrant A penetrates by pushing out the residual air in the sealing material 15.
In addition, if there is no air leakage, the residual air in the sealing material 15 will be trapped due to the pressurized penetration of the penetrant A. Since there is an open groove 10, the residual air in the sealing material 15 is pushed out from the gap 19 by the pressurized infiltration of the penetrant A, as shown in FIG. Since the air passes through the pipe and escapes into the front space of the front pig 1, the replacement effect between air and penetrant A is ensured, and the penetrant A
is deeply penetrated into the entire area of the sealing material 15.

When the impregnating action of the penetrant A on one pipe joint 13 (or 14) is finished, the pigs 1, 2,
3, the negative pressure in front of the front pig 1, and the rope 8
It is moved within the existing pipe 12 by pulling the pipe.

Through this process, the sealing material 15 is filled with penetrant A for each pipe joint, and during this time, the amount of residual penetrant A decreases, but due to the expansion of bag 4, the final Filling pressure can be applied to the resin up to the stage.

In this way, after the impregnation action of the penetrant A in the first stage is completed, the front pig 1
A high viscosity resin putty agent B is placed in the space facing the intermediate pig 2.
Fill it with water and move it within the existing pipe 12 as described above, and when the front pig 1 moves to the position shown in FIG. The filling pressure is applied to the putty agent B through the bag 4 while the system is temporarily stopped or at a low speed. In this case, a surplus of the previous penetrant A remains in the gap 19, but as shown in FIG.
Since a suction force is applied from the front of the front pig 1 through the groove 11 and a filling pressure is applied to the putty agent B, the putty agent B is replaced and filled through the groove 11.

In such an embodiment, the penetrating agent impregnated under pressure in the first stage acts as a lubricant for the filling of the putty agent in the second stage, so even if the putty agent is a high viscosity resin, Resin filling can be achieved reliably, and even if the surface between the pipe joints is uneven,
The adhesion of the putty agent is good, and the effects of improving both the airtight effect and the sealing effect of the putty agent can be obtained.

When repairing a pipe joint using the above-mentioned device, when the pigs 1 and 2 filled with resin pass through the branch opening of the branch pipe 25 provided in the existing pipe 12, resin (penetrating agent) is added to the branch pipe 25. A, the putty agent B) flows in and blocks the branch opening, resulting in an inconvenience. This phenomenon is noticeable, for example, when the front pig 1 is moved by applying negative suction pressure to the front in the moving direction of the front pig 1. That is, when the suction negative pressure is applied, the negative pressure also extends into the branch pipe 25, so that when the front pig 1 passes through the branch opening of the branch pipe 25, the negative pressure remains in the branch pipe 25. Therefore, when the branch opening of the branch pipe 25 faces the resin-filled portion between the front pig 1 and the intermediate pig 2, the residual negative pressure acts to suck the resin (Fig. 6). reference).

However, in this case, according to the invention, the intermediate pig 2
A vacuum chamber 2 is provided between the rear pig 3 and the rear pig 3 in the direction of movement.
2 is formed, and when the pig is moved and the branch opening of the branch pipe 25 is in a position facing the vacuum chamber 22, the required negative pressure is supplied to the vacuum chamber 22 from the negative pressure source 24 via the hose 23. Since the pressure is supplied, the resin that has flowed into the branch pipe 25 due to this negative pressure action flows into the vacuum chamber 2.
(See Figure 7). Incidentally, since the supply of negative pressure to the vacuum chamber 22 is performed based on the detection signal of the sensor 26 that detects the position of the branch pipe 25 in advance, a reliable effect can be expected.

〔Effect of the invention〕

Thus, according to the present invention, when repairing the pipe joint of the existing pipe by passing the resin into the existing pipe through the pig, the resin flows into the branch pipe branched from the existing pipe when the pig moves, and the resin flows into the branch pipe branched from the existing pipe. This eliminates the inconvenience of blocking the branch opening of the tube.

Furthermore, according to the apparatus of the present invention, the inflowing resin sucked out from the branch pipe is collected in the vacuum chamber and taken out of the pipe by movement of the pig, so that the collected resin is also cleaned.

Furthermore, by providing a vacuum chamber in series on the rear side in the direction of movement of the pig, the resin that has flowed into the branch pipe is recovered immediately after flowing in, resulting in effects such as accurate recovery of the inflowing resin. .

[Brief explanation of drawings]

FIG. 1 is a partially cutaway longitudinal side view of one embodiment of the present invention, FIG. 2 is a perspective view of the entire longitudinal section, FIGS. 3 to 7 are action explanatory views, and FIG.
The figure is a perspective view of the pig. 1... Front pig, 2... Intermediate pig, 3... Rear pig, 4... Flexible bag, 5... Pressurized air supply hose, 6... Space, 7... Air supply hole, 8, 9
...Tow rope, 10, 11... Groove, 12...
Existing pipe, 13, 14... Pipe joint part, 13a... Large diameter part, 13b... Pipe end, 15... Sealing material, 1
6...lead material, 18...sensor, 19...between, 2
2...Vacuum chamber, 23...Negative pressure supply hose, 24...
... Negative pressure supply source, 25 ... Branch pipe, 26 ... Sensor,
A... Penetrant, B... Putty agent.

Claims (1)

[Scope of Claims] 1. A means for filling and moving resin between at least a pair of front and rear pigs that slide in airtight contact with the inner surface of the pipe is provided in the pipe of the existing pipe, and in the process of moving the pigs, the existing pipe When the pipe joint is located between the front and rear pigs, the pipe joint is repaired by applying filling pressure to the resin, and a negative pressure supply source of the required pressure is installed on the rear side in the direction of movement of the pair of front and rear pigs. A vacuum chamber is formed which communicates with the pipe through a communication path having an opening/closing mechanism, and a sensor is provided to detect the branch opening of a branch pipe branching from the existing pipe, so that when the pig is moved, the branch opening communicates with the vacuum chamber. A pipe joint repair device for an existing pipe, characterized in that the opening/closing mechanism is configured to open the opening/closing mechanism to supply negative pressure from the negative pressure supply source to the vacuum chamber when the opening/closing mechanism is in the opposing position.