JPH0156313B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is designed to ensure sealing from the inner surface of the pipe joint part of an existing gas pipe that 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 and reinforce the pipes against corrosion and the like while the pipes are buried. In particular, with existing gas pipes buried underground, cast iron pipes are fitted with water type fittings or G
In pipes connected by type joints, the sealing properties of the pipe joints have deteriorated, requiring 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. Deterioration of sealing performance was not a particular problem because it penetrated into the sealing material called "hemp skin," but in the case of dry natural gas, the sealing material dries and shrinks, creating voids and causing the seal to deteriorate. Since this deteriorates the sealing performance of the pipe joint and causes gas leakage, it is necessary to ensure the sealing performance of the pipe joint and perform repairs to prevent seal deterioration in the future.

[Problem to be solved by the invention]

However, for existing gas pipes that have a medium diameter or small diameter, workers cannot enter the pipe and repair the inner surface of the pipe joint like they can for large diameter pipes, so repair work is difficult. Construction is difficult, and there is a need for a construction method in which a worker is outside to repair the inner surface of the joint of the pipe while it is buried.

The present invention was made based on the above circumstances, and when passing a pig into an existing pipe, first, at the pipe joint part, negative pressure suction is used to remove air from the sealing material and the gap in the pipe joint part, and The present invention aims to provide a pipe joint repair device for an existing pipe in which the pipe joint can be repaired from the inside of the pipe in sequence by immediately filling the pipe with resin at a required filling pressure and moving the pig. .

[Means to solve the problem]

In order to achieve this object, the present invention forms two chambers in the front and back in a pig that slides in airtight contact with the inner surface of the existing pipe, and a resin that opens toward the rear side is formed on the outer periphery of the pig part between these two chambers. A filling groove and a substitute escape groove opening toward the front are provided so as to overlap with each other in the axial direction and at different positions in the circumferential direction, and the front chamber is used as a negative pressure chamber. The rear chamber is used as a resin filling chamber, and the resin filling chamber is provided with a flexible bag capable of expanding its volume, so that positive pressure can be applied to the flexible bag to apply filling pressure to the resin in the resin filling chamber. It is characterized by having the following configuration.

[Effect]

With the above configuration, the positive pressure applied to the flexible bag is adjusted by increasing or decreasing the amount of resin in the resin filling chamber, and the pipe joint portion is filled with resin almost constantly. Moreover, reinforcement work can be performed without significantly changing the moving speed of the pig.

〔Example〕

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

In the figure, reference numeral 1 denotes a cylindrical pig, and a towing rope 2 passes through the center of the inside, and is fixed to support disks 3, 3 provided at the front and rear ends of the pig 1. The pig 1 has three pig parts 4, 5, and 6, front, middle, and rear, which are continuous with small-diameter body parts 7, 8 to form an integral structure. A negative pressure supply pipe 9 is opened through the front pig part 4 and communicated with a first chamber formed between the pig parts 4 and 5, and the negative pressure supply pipe 9 is a flexible hose. It extends forward in the direction of movement of the pig 1 and is connected to the vacuum pump 10 (see FIG. 3). In this way, the pig part 4,
The first chamber between 5 and 5 constitutes a negative pressure chamber 11.

Further, a positive pressure supply pipe 12 is communicated with a second chamber formed between the pig parts 5 and 6 by penetrating the front side pig part 4 and the intermediate pig part 5, and the positive pressure The supply pipe 12 is composed of a flexible hose, extends forward in the direction of movement of the pig 1, and is connected to the compressor 13. An inflatable cylindrical flexible bag 14 made of a rubber membrane or the like is disposed concentrically between the pig parts 5 and 6, and partitions the second chamber into the inside and outside. The positive pressure supply pipe 12 is opened on the inside of the housing. The inside of this flexible bag 14 is used as a pressurizing chamber 15, and the outside is used as a resin filling chamber 16.

As shown in detail in FIG. 2, the intermediate pig portion 5 has, on its outer periphery, a resin filling groove 17 that opens toward the rear in the direction of movement, and a replacement groove that opens toward the front in order to provide the function described later. The object escape grooves 18 are arranged in such a manner that their opposing ends overlap in the axial direction, and both grooves 1 in the circumferential direction.
7 and 18 are formed at different positions so that they do not communicate with each other.

In addition, as shown in Fig. 3, in front of pig 1,
Magnetic sensor block 1 is separated by a predetermined distance.
9 is fixed to the traction rope 2. This magnetic sensor block 19 is provided with a plurality of magnetic sensors 20 at divided positions in the circumferential direction.
The signal sending cable 21 extends forward. The towing rope 2 is provided with a scale for measuring its length, and is wound around winches 22 and 23 at the front and back, respectively.

The repair device having such a configuration is used for repairing the inner surface of the existing pipe A in the following manner. Here, the existing pipe A buried underground is a long cast iron pipe connected via pipe joints B and C, such as water type pipes, using a conventional piping method. This existing pipe A
When repairing the pipe joints B and C, in the present invention,
Existing pipe A is divided into length units suitable for repair. Then, a plurality of pipe joints B and C interposed within this section are repaired in a series of repair processes.
For example, the large-diameter part B ₁ provided at the end of one existing pipe A abuts the pipe end B ₂ of the other existing pipe A, and the butt-fitting part is usually called "hemp skin". It has a connection structure in which a sealing material D is filled in and the opening is sealed with a lead material E, and a slight gap F is left at the abutting ends. In addition, the pipe joint part C is connected to the existing pipes A facing each other.
A large-diameter pipe fitting member C ₁ is fitted so as to cover the end of the pipe, and the fitting part with the existing pipe A is filled with sealing material D, and the opening is sealed with lead material E. This connection structure has a slight gap F left at the abutting ends.

The pig 1 is introduced into the existing pipe A to be repaired through one opening. In the present invention, the resin filling chamber 16 is filled with, for example, a penetrating agent Filling putty Y
is filled and transported along with the pig 1 inside the existing pipe A by being pulled by the towing rope 2.

In the first stage, as shown in FIG. 4, the filling chamber 16 is filled with the penetrant X and is moved in the direction of the arrow. This movement is performed by winding the tow rope 2 in with the winch 22. During this movement process, when the magnetic sensor block 19 comes to the position of the pipe joint B (or C), all the magnetic sensors 20 respond and output a signal, which can be captured on the ground. If only one magnetic sensor 20 reacts, it can be detected that the branch pipe is connected. Based on the reaction of this sensor 20 confirming the position of the pipe joint part B (or C), when the pig 1 moves to the position of the pipe joint part B (or C), the pig 1 at this position Pause or slow down movement.

And the stairs where the front pig part 4 passed through the pipe joint part B (when the negative pressure chamber 11 corresponds to the pipe joint part B)
(See Figure 4) When negative pressure is applied to the negative pressure chamber 11 by the action of the vacuum pump 10, negative pressure is applied to the gap F and the sealing material D of the pipe joint part B, and air is sucked together with the dust there. do. Continue to apply negative pressure to negative pressure chamber 11
When the intermediate pig portion 5 comes to the position corresponding to the pipe joint B as shown in FIG. 5, the movement of the pig 1 is temporarily stopped or brought to a low speed state as described above. do. In this state, since the grooves 17 and 18 are opposed to the gap F on the outer periphery of the intermediate pig portion 5, the negative pressure chamber 11 is connected to the gap F and the grooves 17 and 18 in the filling chamber 16.
8, the communication is established. If air remains in the filling chamber 16, this is also removed by suction with negative pressure. The penetrating agent X in the filling chamber 16 is expanded by the volume expansion of the flexible bag 14 by applying positive pressure from the compressor 13 to the pressurizing chamber 15 inside the flexible bag 14 via the positive pressure supply fitting 12. Under filling pressure, it is supplied to the gap F via the groove 17,
The air in the gap F is drawn into the negative pressure chamber 11 by the negative pressure and permeates into the sealing material D. In this case, pressurized air of +0.5 kg/cm ² may be supplied to the pressurizing chamber 15, for example.

At this time, if there is an air leak in the pipe joint B (or C), the penetrant X will penetrate by pushing out the residual air in the sealing material D, and
If there is no air leakage, it is expected that the residual air in the sealing material D will be trapped due to the pressurized penetration of the penetrant The negative pressure suction force of the chamber 11 acts on the gap F and the sealing material D through the grooves 18. Therefore, the residual air in the sealing material D is pushed out by the pressurized infiltration of the penetrant X. From F in the pipe circumferential direction, passing through the groove 18 to the negative pressure chamber 11
Since the penetrating agent X escapes into the sealing material D, the substitution effect between the air and the penetrating agent X is reliably performed, and the penetrating agent X is deeply penetrated into the entire area of the sealing material D.

When the impregnating effect of the penetrant A on the sealing material D for one pipe joint part B (or C) is completed, the negative pressure and positive pressure are reduced, and the pig 1 is pulled by the towing rope 2 again to remove the existing pipe A. (See Figure 6).

In this case, although the negative pressure to the negative pressure chamber 11 may be maintained, it is desirable to reduce the positive pressure applied to the pressurized chamber 15. This is because when filling pressure is applied to the filling chamber 16 while moving through the existing pipe A, the penetrating agent (filling putty in the case of the second stage described below) is forced into the branch pipe at the branch pipe communication section. This is because there is a risk that the branch pipe communication portion will be clogged. However, regarding the branch pipe communication section,
Of course, if other measures are taken, the pig 1 may be moved within the existing pipe A while being continuously loaded with both negative pressure and positive pressure.

Through such a process, the penetrant X permeates the sealing material D for each pipe joint part B, but
During this time, the amount of residual penetrant X decreases. However, this expansion of the flexible bag 14 can substantially apply filling pressure to the resin until the final stage.

In this way, when the impregnation action of the penetrant X in the first stage is completed, the filling chamber 1 is
6 is filled with a high-viscosity resin putty Y, and moved within the existing pipe A in the same manner as in the first step described above, so that the pig 1 is in the specified position relative to the pipe joint B (or C). When moving, the movement is temporarily stopped or at a low speed, and the putty agent Y is pressurized and filled (see FIG. 7). In this case, a surplus of the previous penetrant X remains in the gap F, but the groove 18
, and since filling pressure is applied to the putty agent Y, the putty agent Y is filled through the grooves 17 instead of being pulled down.
Replacement is achieved.

Moreover, the surplus of the penetrating agent Filling can be achieved reliably, and even if the inner surface of the gap F of the pipe joint B (or C) is rough with unevenness, the putty Y has good adhesion and has both an airtight effect and a gap sealing effect. can be increased.

In this embodiment, a pressure sensor is provided near the ground compressor in the negative pressure chamber 11 or on the extension of the negative pressure pipe 9, so that negative pressure fluctuations in the negative pressure chamber 11 can be detected. It's okay. This helps in confirming the presence of the branch pipe by the negative pressure drop that occurs when the pig 1 passes through the branch pipe connection. By detecting this fluctuation and stopping pressurizing the pressurizing chamber 15 and returning the pressurizing chamber 15 to atmospheric pressure, the resin in the filling chamber 16 is prevented from flowing into the communication section of the branch pipe, and the clogging is prevented. It can have the function of preventing

Further, in this embodiment, the pig 1 is constituted by an integral structure having two chambers, but the front pig part 4, the intermediate pig part 5, and the rear pig part 6 are each constructed separately. , of course, may be configured to be connected to each other. Alternatively, the pig may be moved at a constant speed without detecting the pipe joint portion using the magnetic sensor.

〔Effect of the invention〕

As described in detail above, when passing a pig into an existing pipe, the present invention first uses negative pressure suction at the pipe joint to remove air from the sealing material and the gap in the pipe joint, and immediately after that, the resin is removed. By filling with the required filling pressure and moving the pig, the pipe joint can be successively repaired from the inside of the pipe, and the pipe joint can be reliably and completely sealed. Furthermore, since the resin pressure is adjusted using the flexible bag, there is no need to greatly change the moving speed of the pig, allowing for efficient repair work.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of the present invention;
FIG. 2 is a perspective view of the same, FIG. 3 is an overall longitudinal sectional perspective view showing how it is used, and FIGS. 4 to 6 are partially enlarged longitudinal sectional views illustrating the penetration state of the penetrant in the first stage.
FIGS. 7 and 8 are partially enlarged vertical cross-sectional views illustrating the state of penetration of the penetrant in the second stage. 1...Pig, 2...Tow rope, 3...Disc,
4,5,6...Pig part, 7,8...Body part, 9...
... Negative pressure supply pipe, 10 ... Vacuum pump, 11 ... Negative pressure chamber, 12 ... Positive pressure supply pipe, 13 ... Compressor, 14 ... Flexible bag, 15 ... Pressure chamber, 16
...Filling chamber, 17, 18...Groove, 19...Block, 20...Sensor, 21...Cable, 2
2, 23...Winch, A...Existing pipe, B...Pipe joint part, _B1 ...Large diameter part, _B2 ...Pipe end, C...
Pipe joint part, D...Sealing material, E...Lead material, F...
Gap, C ₁ ... Pipe joint member.

Claims (1)

[Scope of Claims] 1. A pig that slides in airtight contact with the inner surface of an existing pipe has two chambers in the front and rear, and a groove for resin filling that opens toward the rear on the outer periphery of the pig portion between the two chambers. and a groove for escaping the substituted substance which opens towards the front side, are provided in such a manner that they overlap with each other in the axial direction and at different positions in the circumferential direction, so that the front chamber is a negative pressure chamber, and the rear chamber is a negative pressure chamber. The chamber is used as a resin filling chamber, and the resin filling chamber is provided with a flexible bag capable of expanding its volume, and is configured such that positive pressure can be applied to the flexible bag to apply filling pressure to the resin in the resin filling chamber. A pipe joint repair device for existing pipes, which is characterized by: