JPH0542313B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention primarily relates to a repair method for plugging holes due to corrosion in small diameter pipes attached to existing buried main pipes.

Conventional technology and problems There is currently no suitable repair method for plugging holes caused by corrosion in small-diameter pipes attached to existing buried main pipes. After cutting the pipe, the small diameter pipe was removed and replaced. There is also a lining method in which pressurized fluid is used to push the lining material inserted between two pigs, but with this method, the hole is temporarily closed when the pig passes, but after the pig has passed, the pressurized fluid The drawback was that the lining agent that was blocking the hole was blown away.

In order to solve these problems, the applicant has previously developed a method for repairing leaks in small diameter pipes, as disclosed in Japanese Patent Application No. 101893/1983. This method involves blowing compressed air from behind a wire extension line that has an umbrella-shaped pig at the tip, inserting the line into a small-diameter pipe, and inserting a guiding wire into the small-diameter pipe using the line. Then, as shown in Figure 3A, connect the front and rear pigs at a predetermined interval, and pull the wire through the small diameter pipe with high viscosity repair agent filled between both pigs to locate the leak hole. In this method, the repair agent that is blown outward from the leakage hole automatically hardens in that area and closes the hole without detecting it in advance. This method has been practically confirmed to be very effective as a repair method for leakage holes caused by general corrosion.
When the hole caused by corrosion is large, as shown in FIG. 3B, even if this method is repeatedly repaired, the repair agent that has blown outward drips down before hardening, and the hole may not be closed.

Means for Solving the Problems The small diameter pipe leak repair method of the present invention has the following configuration as a means for solving the above problems.

(1) A rubber bag for airtightness inspection with a guidance wire connected to the front end and a pressure tube connected to the rear end is pulled to the end of the pipe, and then returned from the end of the pipe at a fixed interval to remove the rubber bag for security inspection. A leak hole position discovery process in which internal pressure is applied to bring the pipe into close contact with the inner wall of the pipe, and air pressure is applied to the pipe at regular intervals to inspect the airtight state, and this process is repeated to confirm the presence or absence of leakage in a certain section. Then, introduce a considerable amount of high viscosity repair agent sandwiched between two pigs attached to the guide wire to the position of the leak hole, pull out the guide wire, and let the repair agent harden in that state. The filling process is combined with a boring process in which a hole is made in the cured repair agent using a boring device having a boring tool at the tip of a flexible shaft.

(2) The above two pigs are made of high-density foamed urethane and both have the same diameter as or larger than the pipe inner diameter, and the front pig is installed without being fixed to the wire, and the rear pig is fixed to the wire.

Function The present invention uses the method disclosed in Japanese Patent Application No. 62-101893 to insert a guiding wire into a pipe, detects the position of a leakage hole using the guiding wire, and detects the position of a leakage hole by using the guiding wire. A highly viscous repair agent is filled and hardened inside the leak hole using two pigs, and then a boring machine is used to drill the hole.As with the conventional method, the lining agent is blown away by pressurized fluid. This prevents the problem of the hole not being closed due to leakage or dripping of the repair agent, allowing for reliable leakage repair.

As the high viscosity repair agent, for example, a two-component mixed metal powder-containing epoxy resin having a specific gravity of 1.6 to 1.8, a viscosity of 70,000 to 100,000 cp, and a curing time of about 1 hour, as well as various other materials can be used.

Embodiment FIGS. 1A and 1B are cross-sectional views showing an example of the leak hole position discovery process in the method of the present invention, in which 1 is a small diameter pipe, 2 is a guiding wire, 3 is a rubber bag for airtightness inspection, 4 is a pressure tube, and 5 is an LA coupling. As shown in FIG. 1B, air pressure is applied to the pressure tube 4 at a certain distance from the end of the tube to inflate the rubber bag 3 and bring it into close contact with the inner surface of the small diameter tube 1, and then air pressure is applied to the LA coupling 5. The presence or absence of a decrease in the air pressure is inspected, and if there is no decrease, the rubber bag 3 is moved to the next point at a certain interval and the same inspection is performed, and by repeating this operation, the location of the leak hole can be discovered. can.

FIGS. 2A and 2B are cross-sectional views showing an example of the repair agent filling process of the method of the present invention. Using the guiding wire 2 used in FIG. After inserting the pig 6, the high viscosity repair agent 7 is moved while the pig 6' is fixed, and then the wire 2 is pulled out and hardened in the state shown in FIG. 2B.

FIGS. 2C and 2D are cross-sectional views showing one example of the boring process of the method of the present invention, in which the hardened repair agent 7 is bored from one side by a boring device 8 having a drilling tool 8b at the tip of a flexible shaft 8a. Then, the bore hole 7a is bored.

Effect of the invention (1) The location of leakage holes in small diameter pipes can be confirmed.

(2) Even if the leak hole is large, the repair agent will not drip and can be repaired reliably.

[Brief explanation of the drawing]

FIGS. 1A and 1B are cross-sectional views showing one example of the leak hole position finding process of the present invention, and FIGS. 2A to D are one example of the repair agent filling process of the present invention, and one example of the boring process.
3A and 3B are sectional views showing conventional examples. The symbols in the drawings indicate the following members, respectively. 1: Small diameter tube, 2: Guidance wire, 3: Rubber bag for airtightness inspection, 4: Pressure tube, 5: LA
Coupling, 6, 6': Pig, 7: Repair agent,
8: Bowling equipment.

Claims (1)

[Claims] 1. A rubber bag for airtightness inspection with a guiding wire connected to the front end and a pressure tube connected to the rear end is pulled to the end of the pipe, and then returned from the end of the pipe at a fixed interval to perform the airtightness test. Applying internal pressure to the rubber bag used to make it stick to the inner wall of the pipe, and applying air pressure inside the pipe at regular intervals to check the airtightness, and repeating this process to check whether there is a leak in a certain section. a position finding step, and then a considerable amount of high viscosity repair agent sandwiched between two pigs attached to the guiding wire is guided to the position of the leak hole,
A repair agent filling process in which the guiding wire is pulled out and cured in that state, and a boring process in which a hole is made in the cured repair agent using a boring machine equipped with a drilling tool at the tip of a flexible shaft are combined. A method for repairing small-diameter piping leaks. 2. The two pigs are made of high-density foamed urethane and both have the same diameter as or larger than the inner diameter of the pipe, and the front pig is attached without being fixed to the wire, and the rear pig is fixed to the wire. The method for repairing small-diameter piping leaks as described in Item 1.