JPH01104370A - Method of repairing leak in small diameter piping and repaired small diameter piping - Google Patents

Abstract

PURPOSE:To perform secure repairing work by detecting the position of a leak hole, arranging a pig device at prearranged position, inserting a flexible tube from a tube end and injecting high-viscosity repairing agent through an LA coupling. CONSTITUTION:A rubber bag is inflated by applying an air pressure to a pressure-resistant tube at a fixed interval from a tube end so that the rubber bag is caused to adhere to the inner surface of a small diameter pipe 1 closely. Then an air pressure is applied to an LA coupling 5 to detect the position of a leak hole. After this, wire 2 with a pig device 6 is introduced into the pipe and a flexible tube 7 is inserted into the pipe through its end. Next, high- viscosity repairing agent 8 is injected through the LA coupling 5. Later the wire 2 is pulled out and the pig device 6 is shaved off after the curing of the agent. Thus the repairing agent does not drip through an secure repair is assured even when a leak hole is large.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention primarily relates to a repair method for plugging holes caused by corrosion in small-diameter pipes attached to existing buried wood pipes, and to the repaired small-diameter 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 out the small diameter 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 in this method, when the pigs pass through, the holes are temporarily blocked, but after the pigs have passed, the pressurized fluid This had the disadvantage that the lining agent that was blocking the hole was blown away.

In order to solve these problems, the applicant has filed a patent application filed in 1983-
Developed a method for repairing small-diameter pipe leaks in No. 101-893. 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 3 (A), connect the front and rear pigs at a predetermined distance, and pull the wire through the small diameter pipe with the high viscosity repair agent filled between the two pigs to remove the leakage hole. In this method, the leakage hole is automatically hardened using the repair agent that has blown outward from the leakage hole without having to discover the location of the leakage hole in advance. This method has been practically confirmed to be very effective as a repair method for general leakage holes caused by corrosion. Even after repeated repairs, there were cases in which the repair agent that gushed out to the outside dripped in before it hardened and the hole was not closed.

Means for Solving the Problems The small diameter pipe leak repair method and the repaired small diameter pipe of the present invention have the following configurations as 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 back 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 airtightness testing. Applying internal pressure to the bag to bring it into close contact with the inner wall of the pipe, and applying air pressure inside the pipe at regular intervals to inspect the airtight state, repeating this process to find the location of the leak hole to confirm the presence or absence of leakage in a certain section. In this process, the pig fixed to the guide wire is inserted from the tube end to a position with sufficient margin relative to the leakage hole position, and then a flexible tube is inserted from the tube end and its tip is inserted. a tube insertion step of bringing the wire into contact with the pig; a repair agent injection step of injecting a high viscosity repair agent between the flexible tube and the small diameter tube through an LA coupling provided at the tube end; A repair method that combines a extraction process and a pig removal process in which the pig is scraped off using a polling device after the repair agent has hardened.

(2) Insert a flexible tube into a small-diameter pipe in which a leak hole is suspected to exist, and apply a high-viscosity repair agent to the flexible tube and the small-diameter pipe through an LA coupling installed at the end of the small-diameter pipe. A repaired small-diameter pipe that is injected between the pipe and hardened.

Function The present invention uses the method disclosed in Japanese Patent Application No. 101893/1983 to insert a guiding wire into a pipe, detects the position of a leakage hole using the guiding wire, and inserts a wire into the guiding wire. A method of partially repairing by placing a fixed pig in a position with sufficient margin beyond the leak hole and injecting a high viscosity repair agent from the LA cup link on the pipe end side, and using the above-mentioned guiding wire. This method targets small-diameter pipes that have been repaired by inserting a flexible wire through all of the small-diameter pipes that are suspected of having leakage holes, and then injecting a repair agent.

The high viscosity repair agent is, for example, a two-component heating type epoxy resin mixed with metal powder, with a specific gravity of 1.6 to 1.8 and a viscosity of 70.
000~Zoo, 000 cp, curing time of about 1 hour, and various other types can be used.

As the flexible tube, for example, in addition to one produced by drawing from a pipe, a flat spiral tube formed by spirally forming a metal strip can also be used.

Embodiment FIGS. 1(A) and 1(B) are cross-sectional views showing an example of the step of finding the position of a leak hole in the method of the present invention, in which 1 is a small diameter pipe, 2 is a guiding wire, and 3 is for an airtightness test. There is a rubber bag, 4 is a pressure tube, and 5 is an LA coupling. Figure 1 (B)
Pressure-resistant tubes 4 at regularly spaced points from the tube bundle as shown.
After applying air pressure to inflate the rubber bag 3 so as to bring it into close contact with the inner surface of the small-diameter pipe l, apply air pressure to the LA cow ring 5 and inspect whether or not the air pressure has decreased.If there is no decrease, the following constant The position of the leakage hole can be found by moving the rubber bag 3 to a point at the interval and carrying out a similar inspection, and repeating this operation.

FIGS. 2(A) and 2(B) are cross-sectional views showing an example of partial repair according to the present invention, where l is a small diameter pipe, 2 is a guiding wire, and 5 is an LA coupling. The wire 2 with the pig 6 attached is drawn into the tube, and the flexible tube 7 is inserted from the tube end.
is inserted to a predetermined position, and high viscosity repair agent 8 is injected through LA coupling 5. After injecting the repair agent, the wire 2 is pulled out, and after the repair agent has hardened, the pig 6 is scraped off using a poling device to complete the repair as shown in FIG. 2(B).

FIGS. 2(C) and (D) are cross-sectional views showing one example of overall repair according to the present invention, where l is a small diameter pipe, and a metal flexible tube 7 is inserted over the entire length, and a high The viscosity repair agent 8 is injected and cured to complete the repair.

According to the example, the outer diameter is 27.2+*m and the inner diameter is 19.4m.
A flexible tube with an inner diameter of 10.5 mm was used to perform partial and total repairs on a small-diameter tube with good results.

Also, the outer diameter is 34.0 mm and the inner diameter is 25.0 mm. Good results were obtained when a flexible tube with an inner diameter of 13.0 mm was used to perform overall repair on a small-diameter Os+s tube.

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

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

[Brief explanation of the drawing]

FIGS. 1(A) and 1(B) are cross-sectional views showing one example of the leak hole position finding process of the present invention, and FIG. 2(A). (B) is an example of a partial repair, and (C) and (D) are cross-sectional views of an example of a total repair.
B) is a sectional view showing a conventional example. The symbols in the drawings indicate the following members, respectively. l: Small diameter pipe 2: Guiding wire 3: Rubber bag for airtightness inspection 4: Pressure resistant tube 5: LA force/tube 1 nong 6:
Pig 7: Flexible tube 8: High viscosity repair agent Patent applicant Koyo Construction Kogyo Co., Ltd. Japan Mining Co., Ltd., ':,l,,°',゛,. Masaaki Kobashi 14.
”-1, 112・ノ5P1Figure 3Figure (A)

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 ensure airtightness. A leak test in which internal pressure is applied to a rubber bag for inspection to bring it into close contact with the inner wall of the pipe, and air pressure is applied to the inside of the pipe at regular intervals to test its airtightness, and this process is repeated to confirm whether or not there is a leak in a certain section. In the process of finding the position of the hole, the pig fixed to the guiding wire is inserted from the tube end to a position with sufficient margin relative to the leakage hole position, and then the flexible tube is inserted from the tube end. a tube insertion step in which the tip of the flexible tube is brought into contact with the pig; a repair agent injection step in which a high viscosity repair agent is injected between the flexible tube and the small diameter tube through an LA coupling provided on the tube end side; A small diameter pipe leak repair method characterized by combining the wire extraction step with a pig removal step of scraping off the pig with a boring machine after the repair agent has hardened. 2. Insert a flexible tube into a small-diameter pipe in which a leak hole is suspected to exist, and apply a high-viscosity repair agent to the flexible tube and the small-diameter pipe through an LA coupling installed at the end of the small-diameter pipe. A repaired small-diameter pipe characterized by being injected and hardened between the pipes.