JP3699333B2 - Repair method for existing pipelines - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a method for repairing an existing pipe, and more particularly to a method for drawing a new pipe material into an old pipe.
[0002]
[Prior art]
In a metal pipe such as a cast iron pipe buried in the ground, if a corrosion hole is generated in part due to aging or the like, leakage of gas or the like is caused from that part.
Therefore, in the past, repair work has been carried out for such a part, but as a construction method, a thermoplastic resin tube is inserted into the inner surface, the diameter is expanded at the work part, and the resin tube is attached to the inner surface. There are a method of attaching and a method of applying a resin lining to the inner surface.
In both cases, the material is bonded and integrated with the inner surface of the existing pipe in both cases.
[0003]
[Problems to be solved by the invention]
By the way, although the resin tube and the resin lining film located on the inner surface are in contact with the inner surface, when the adhesive force is reduced, there is a possibility that the existing tube is stopped and the inside of the tube is blocked.
In particular, when a thermoplastic resin tube is coated, not only it is necessary to prepare propane gas as a heat source, but also skill is required for work, and workability is poor. In addition, fire as a heat source is used in the vicinity of the gas flowing in the pipe, which is dangerous and unfavorable in terms of work in relation to the leaked gas.
Therefore, an insertion method is known in which a new pipe material is drawn into an existing pipe line that has deteriorated.
There are the following types of insertion methods.
As a first construction method, as shown in FIG. 4, a pipe material P1 made of a thermoplastic resin is drawn into the existing pipe P in a U-shaped state (see FIG. 4A), and the existing pipe is drawn. As shown in FIG. 4B, there is a construction method that follows the shape of the inner surface of an existing pipe line by introducing high-temperature steam into the pipe material P1 drawn into the path P and expanding it. .
As a second construction method, as shown in FIG. 5, there is a construction method in which a pipe material P2 having a diameter smaller than that of the existing pipeline P is directly drawn into the existing pipeline P.
[0004]
In the first construction method, the pipe material drawn into the existing pipe is folded to reduce the contact area with the existing pipe inner surface, thereby reducing the frictional resistance at the time of drawing and facilitating the drawing work. On the other hand, since the expansion rate is high due to the use of the vapor pressure, for example, it is limited to a case where the diameter is 100 mm or more, and there is a possibility that the equipment for supplying the steam becomes large.
In the second construction method, although the above-mentioned rubbing resistance is increased, since it is not necessary to use steam, the equipment can be simplified. On the other hand, since the pipe material having a smaller diameter than the existing pipe line is used, the flow rate is significantly reduced. There is a fear.
Furthermore, in the case where the above-described method is applied to an existing pipe line composed of a small-diameter pipe of 80A or less, if the radius of curvature of the existing pipe line is small, it becomes difficult to pull in, and the more pipe parts, the new pipe material. There is a risk that it will be difficult to pull in.
[0005]
An object of the present invention is to provide a simple facility for easily pulling in a new pipe material regardless of the number of curved portions and reducing a decrease in flow rate in view of the problems in the conventional repair method for existing pipes. The purpose is to provide a repair method for existing pipelines.
[0006]
[Means for Solving the Problems]
In order to achieve this object, the invention described in claim 1 is a method of repairing an existing pipe line by drawing a new pipe material into the existing pipe line, and sequentially from the center side of the existing pipe inner surface. heating layer, a protective member made of heat insulating layer and the protective layer from the insulation material superimposed respectively provided in the conduit member outer peripheral surface, together with the protective member while softening the pipe material by heating the protective member The pipe material is pulled to draw the pipe material into the existing pipe.
[0007]
According to a second aspect of the present invention, in the repair method for an existing pipe line according to the first aspect, the heating layer contains a metal material capable of dielectric heating or resistance heating.
[0008]
According to a third aspect of the present invention, in the method for repairing an existing pipe line according to the first aspect, when the newly drawn pipe line material is softened by heating by the protection member, the pipe line material is deformed according to the laying form of the existing pipe line. It is characterized in that possible materials are used.
[0009]
The invention according to claim 4 is a method for repairing an existing pipe line according to claim 3,
A thermoplastic resin material is used for the pipe line material.
[0010]
[Action]
In the first to fourth aspects of the invention, since the protective member capable of generating heat is covered with the pipe line material, when the protective member and the pipe line material are pulled while softening the pipe line material, the existing pipe line is installed. The pipe material can be deformed according to the above. In particular, when a curved portion exists in an existing pipeline, the softened pipe material can be deformed into a shape along the curved portion, so that the insertion at the curved portion can be improved. Moreover, since the protective layer of the protective member faces the inner peripheral surface of the existing pipe line on the outer peripheral surface of the pipe line material when being drawn into the existing pipe line, The surface is protected and pulled in without damage.
Furthermore, since the protective member drawn together with the pipe material contains a metal material in the heating layer, the tensile strength is ensured even when pulled and drawn together with the pipe material. For this reason, it is possible to prevent the pipe material that has been softened and easily stretched from being deformed such as mechanical tearing or elongation.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the illustrated examples.
FIG. 1 and FIG. 2 are sectional views in side view showing a construction state of a repair method according to an embodiment of the present invention. In FIG. 1 and FIG. Arranged. FIG. 2 is a cross-sectional view of the existing pipeline 2 as viewed from the front.
[0012]
The protection member 1 is provided in a state of being covered on the outer peripheral surface of the newly drawn pipe line material 5, and the configuration thereof is shown in FIG. 3.
The protection member 1 is a member that also serves to heat and protect the pipe material 5 drawn into the existing pipe line 2, and in order from the inner surface side (the pipe line center side) of the existing pipe line 2, The pipe member is made of a thermoplastic resin provided with the layer 1B and the protective layer 1C, and the outer peripheral surface of the pipe line material 5 is covered by integral molding or the like.
A power supply line 4 connected to the power supply box 3 is connected to the heating layer 1 </ b> A, and heat can be generated by power supply from the power supply box 3. For this reason, for the heating layer 1A, a material such as a metal capable of resistance heating or dielectric heating is used, or a resin containing the metal is used as an aggregate. In the present embodiment, the temperature due to heat generation in the heating layer 1A is maintained at 40 to 80 ° C.
[0013]
The heat retaining layer 1B is made of a material having a high heat conductivity such as polyamide or polyethylene and having a high heat retaining effect, and maintains the temperature due to the heat generated in the heating layer 1A.
The outer peripheral surface of the protective layer 1C is subjected to a treatment for reducing the frictional resistance between the outer peripheral surface and the inner peripheral surface of the existing pipe line 2, and in this embodiment, a smoothing treatment or a heat resistant material such as a fluororesin is used. A low-friction member is provided.
The protective member 1 having the above layers is made thinner than the thickness of the existing pipe line 2 or the pipe material 5 so that the difference between the inner diameter of the existing pipe line 2 and the inner diameter of the pipe material 5 is reduced. Yes.
[0014]
In the present embodiment, a new pipe line material 5 is drawn into the existing pipe line 2 by the following procedure using the protective member 1 having the above configuration.
(1) As shown in FIG. 1 and FIG. 2, the pipe material 5 drawn into the existing pipe 2 is prepared by covering the outer peripheral surface with the protective member 1.
Since the thickness of the protective member 1 is reduced, the difference between the inner diameter of the existing pipe line 2 and the inner diameter of the pipe material 5 to be newly drawn can be reduced. Thereby, the flow volume difference at the time of the pipe line material 5 being drawn in can be made small. Furthermore, since it is thin and can also bend flexibly, the insertion property in the curved part of the existing pipe line 2 can also be improved.
(2) Power is supplied to the heating layer 1A of the protective member 1 and the surface temperature is maintained at 40 to 80 ° C.
(3) The pipe line material 5 is drawn into the existing pipe line 2 while maintaining the temperature of the protective member 1.
In this case, the protective member 1 is pulled together with the pipe material 5 and pulled into the existing pipe line, but the outer peripheral surface of the pipe material 1 is protected by the protective member 1 and the protective layer 1C of the protective member 1 is provided. Since the process of reducing the rubbing resistance between the inner peripheral surface of the pipe line 2 is performed, the pipe member 5 can be pulled in without being damaged and in a state in which the rubbing resistance is reduced.
Since the pipe material 5 is heated by heat transfer from the heating layer 1A of the protection member 1, thermal plastic deformation is possible. For this reason, even if the form of the existing pipe line 2, for example, a curved part exists, since it can be plastically deformed in the softened state, it can be easily inserted along the curved part.
[0015]
According to the present embodiment, a metal material or a resin containing a metal as an aggregate is used as the heating layer 1A. In any case, since a highly rigid material exists, the pipe material 5 is softened. Even in a state where it is easy to stretch, it can be pulled while preventing deformation such as stretching due to the rigidity of the protective member 1. As a result, tearing that occurs when the pipe material 5 expands can be prevented, and changes in the flow rate difference due to changes in the inner diameter can be prevented.
[0016]
【The invention's effect】
According to invention of Claim 1 thru | or 4, after covering the protective member which has a heating layer, a heat retention layer, and a protective layer on the newly drawn pipe line material, when drawing in the existing pipe line with the pipe line material The pipe member is retracted while being softened by the heat generated by the protective member. For this reason, regardless of the laying form of the existing pipe line, the pipe line material can be deformed and drawn in according to the laying form. As a result, the pipe material can be drawn in without requiring large-scale equipment, and the drawn-in pipe material can be pulled in without being damaged. As a result, it is possible to maintain a state in which the flow rate in the pipe line material can be prevented from changing.
[Brief description of the drawings]
FIG. 1 is a side sectional view of an existing pipeline for explaining an execution state of a repair method according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the existing pipeline shown in FIG. 1 when viewed from the front.
3 is a cross-sectional view for explaining a configuration of a protective member used in the repair method shown in FIG. 1, and (A) is a cross-sectional view in side view. (B) is sectional drawing seen from the front.
FIG. 4 is a schematic diagram showing a conventional example relating to a repair method for an existing pipeline.
FIG. 5 is a schematic diagram showing another conventional example relating to a repair method for an existing pipeline.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Protective member 1A Heating layer 1B Thermal insulation layer 1C Protective layer 2 Existing pipe line 3 Power supply box 4 Feed line 5 Pipe line material

Claims (4)

A method of repairing an existing pipe line by drawing a new pipe material into the existing pipe line, in which the heating layer, the heat insulating layer and the protective layer are superposed in order from the center of the existing pipe inner surface. a protective member made of a material provided on the pipe member outer peripheral surface, the conduit member of the existing towing the pipeline material together with the protective member while softening the pipe material by heating the protective member A repair method for existing pipelines, which is drawn into the pipelines. In the repair method of the existing pipeline according to claim 1,
A repair method for an existing pipe line, characterized in that the heating layer contains a metal material capable of dielectric heating or resistance heating. In the repair method of the existing pipeline according to claim 1,
A repair method for an existing pipeline, wherein a material that can be deformed according to the laying form of the existing pipeline is used when the newly drawn pipeline material is softened by heating with the protective member. In the repair method of the existing pipeline according to claim 3,
A repair method for an existing pipe line, wherein a thermoplastic resin material is used for the pipe line material.

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