JPH01279198A - Method for partly repairing pipe conduit from its internal surface - Google Patents

Abstract

PURPOSE:To enable repair to be performed with no use of an adhesive agent by inserting a repairing sleeve, which forms in its external surface a rubber or resin layer able to foam and in an unfoamed condition, into a pipe to its repaired part to be heated thereafter. CONSTITUTION:A repairing sleeve 5, having rigidity and forming in its external surface a resin or rubber layer 7 able to foam and in an unfoamed condition, is inserted into a pipe 1 to its location of a pin hole 2 and heated. Thus because the resin or rubber layer 7 foams fixing the repairing sleeve 5 to an internal surface of the pipe 1, it can be repaired without using an adhesive agent.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This A-mei is a method for applying repair materials to gas pipes, water pipes, or other pipes buried underground when a cause of repair occurs in these pipes. This relates to a method of partially repairing the inside of the surface.

[Prior art] As a repair method when corrosion occurs in a part of a gas pipe, etc. or a cause of leakage occurs, there is a method of partially repairing a gas pipe by applying a repair material to the inner surface of the pipe (Japanese Unexamined Patent Publication No. 58 -17
278) is well known.

This known example is a repair method in which adhesive is sprayed onto the area that requires repair to form an adhesive layer, and a ring-shaped thermoplastic repair material that has been softened by heating is expanded in diameter and adhered to the adhesive layer. It is.

[Problems to be Solved] However, in this known example, since an adhesive is used as a means for tightly adhering the repair material to the inner surface of the pipe, there are the following problems.

a. Due to deterioration or chemical changes in the adhesive, the adhesive strength decreases and the repair material peels off after one hour, requiring repeated repairs.

b. In order to form an adhesive layer on the inner surface of the pipe by injecting adhesive, for example, if this work is performed while the fluid is passing through the pipe, the adhesive will get mixed into the fluid and the valve will be damaged on the downstream side. It cannot be repaired with fluid flowing through it because it may adhere to the aircraft base and cause trouble.

As a result, there are restrictions, especially when applied to pipe repair for city gas, water, etc. There are many B terms.

It is necessary to expand the diameter of the repair material and press it until the C1 adhesive hardens, which takes time.

The present invention has been proposed in view of the above points, and its purpose is to propose a method for partially repairing a pipe from its inner surface without using an adhesive. .

[Means for Solving the Problems] The present invention proposes the following repair method as a means for solving the above problems.

A rigid repair sleeve with a foamable, unfoamed resin or rubber layer formed on its outer surface is inserted into the pipe to the repair location, and then the unfoamed resin or rubber layer is heated and foamed. A method of partially repairing a pipe from the inner surface by fixing a repair sleeve to the inner surface of the pipe.

As the heat-foamable resin or rubber layer formed on the outer surface of the repair sleeve, a layer containing transpolyisoprene as a main component can be considered, for example.

Further, the resin or rubber layer formed on the outer surface of the repair sleeve may be made of foamable resin or immersion liquid wrapped in a rubber-like membrane having airtight and watertight properties.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, l is a pipeline buried underground, such as a gas pipeline or a water pipe. The repair of this pipe 1 is carried out as follows.

It is assumed that a pinhole 2 or the like is generated in a part of the conduit I as shown in Fig. 51.

First, a working hole 3 is excavated, the pipe l is exposed and cut in the hole, and from this cut hole 4 toward the pinhole 2, etc., foaming material tb is applied to the outer surface of the pipe in an unfoamed state. A repair sleeve 5 having a rigidity and having a resin or rubber layer 7 formed thereon is inserted. As shown in FIG. 2, the repair sleeve 5 is made up of a rigid repair sleeve main body 6 and an unfoamed resin or rubber layer 7 formed on the outer surface of the repair sleeve.

The resin or rubber layer 7 can be made of a wide variety of rubber materials such as nitrile rubber and silicone rubber, which are commonly used as sealing materials, and resin materials such as polyethylene and polystyrene with a foaming agent added thereto. .

It is preferable to form a closed cell structure and maintain airtightness during one foaming process. This can be done by generating nitrogen gas using an organic foaming material such as an N-nitroso compound or an azo compound.

In addition, since it is easy to handle at a relatively low temperature of 60°C, a sheet formed is wrapped around the outer periphery of the repair sleeve main body 6, and transpolyisoprene is used as a material that maintains rigidity and durability even after foaming. Used or preferred.

To explain in detail, it is preferable to use a transpolyisoprene resin with a blowing agent of dinitrosopentamethylenetetramine (DPT>) and a urea-based auxiliary agent added.

In order to insert this repair sleeve 5 into the pipe line l, for example, as shown in FIG. 3, a carrier 8 is used. This transport vehicle 8 is equipped with a heating heater 9 at the front, and the repair sleeve 5 is attached to the outside of the heating heater 9, and the repair sleeve 5 is attached to the outside of the heating heater 9.
A transport vehicle 8 is manually inserted into the pipe line l through a cutting opening 4 opened at one end of the pipe, and is stopped at the repair location.

The location of the repair location has been searched in advance, and based on this data, the carrier 7 on which the repair sleeve 5 is mounted is positioned at a predetermined position.

Then, the heater 9 is energized and heated to foam the resin or rubber layer 7, filling the gap between the inner surface of the pipe l and the repair sleeve 5, and fixing it by the compressive force generated therebetween. It is something to do. after that,
The transport vehicle 8 is pulled out of the area and the repair work is completed. The completion status of this repair is shown in Figure i4.

At this time, the repair sleeve main body 6 can be easily foamed at the temperature required to foam not only commonly used metals such as tin and stainless steel, and non-metallic materials such as ceramics, but also unfoamed materials. Any material that does not soften and is rigid at room temperature is sufficient, and synthetic resins that have both heat resistance and rigidity, such as polyamideimide, polyimide, and fluorocarbon resin, can also be used.

As shown in the embodiment described above, by using the carrier 8, the repair sleeve 5 can be inserted quickly and without damage, and since the carrier 8 is hollow in the center, it does not block the flow of gas inside the pipe. It is.

As shown in FIG. 4, instead of the wood 1 or the rubber layer 7, a rigid sleeve material, that is, an airtight material fixed to the outer surface of the repair sleeve main body 6 at both ends thereof, is used.
It is also possible to use a liquid foamable resin or rubber 11 wrapped in a watertight rubbery membrane IO.

In this case, the above-mentioned foaming agent is added to a generally known liquid resin or rubber such as liquid polyurethane or silicone, and a layer comparable to that of the above-mentioned resin or rubber layer 7 can be obtained.

Here, the rubber-like membrane 10 is desirably made of a material that easily expands under low pressure, such as elastomers such as polyurethane and polyester, natural rubber, litrile rubber, and the like.

The rubber membrane 10 can form a seal between the inner surface of the tube and the foam layer, thereby increasing the airtightness of the repaired area.

[Effects of the present invention] According to the present invention, a. The repair sleeve is fixed between the repair sleeve main body and the inner surface of the pipe line by the compressive force of the resin or rubber foamed between them. By using adhesive to apply the repair material, there is no need to worry about the adhesive degrading and peeling off from the repair sleeve.

b. Since no adhesive is used as in the conventional method, repair work can be carried out while fluid is still flowing through the pipe.

C0 Since no adhesive is used as in conventional methods, there is no need to hold the C repair sleeve while the adhesive hardens.
Work time can be shortened.

d1 Compressive force of foamed resin or rubber 'C Since the repair sleeve is fixed, there is no need for a device for expanding the diameter of the repair material as in the past, and it can be applied to small diameter pipes.

e, 9. By composing the foam layer with transpolyisoprene resin, even if a pinhole in the pipe becomes large and external pressure is applied directly to the repair sleeve, there is no need to worry about buckling, etc., and the pipe is sufficiently strong. It has the effect of ensuring

``If the foam layer is made of liquid and covered with a rubbery membrane, it will be more airtight.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a situation in which a work hole is excavated for repair work in an existing pipeline, Fig. 2 is a side view showing an embodiment of a repair sleeve according to the present invention, and Fig. 3 is a diagram of the present invention. FIG. 4 is an explanatory diagram showing the state in which the repair sleeve has been inserted up to the repair point in the pipe line, and FIG. 4 is an illustration showing the state after repair [A, and FIG. 5 is a diagram of another embodiment of the repair sleeve. l... Pipe line buried underground 2... Pinhole etc. 3... Work hole 4... Cutting opening 5... Repair sleeve 6... Repair sleeve body 7... Unfoamed resin or rubber layer 8...
...Carrier 9...Heating heater lO...Rubber membrane 11...Liquid foamable resin

Claims (3)

[Claims] (1) After inserting a rigid repair sleeve with a foamable, unfoamed resin or rubber layer on its outer surface to the repair point inside the pipe, heat the unfoamed resin or rubber layer. A method of partially repairing a pipe from the inner surface by fixing a repair sleeve to the inner surface of the pipe by foaming. (2) A method for partially repairing a pipe from the inner surface according to claim 1, wherein a repair sleeve is used in which the resin or rubber layer formed on the outer surface of the repair sleeve is made of transpolyisoprene as a main component. (3) The pipe line according to claim 1, wherein a repair sleeve is used in which the resin or rubber layer formed on the outer surface of the repair sleeve is made of a foamable resin or rubber liquid wrapped in a rubbery membrane having airtight and watertight properties. A method of partially repairing it from the inside.