JP2003185085A - Regenerating and repairing method of piping for hot water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a regenerating and repairing method of piping for hot water, which can respond to corrosion in a pipe caused by vapor, and in which harmful substance does not flow out into the hot water flowing in the pipe. <P>SOLUTION: A corrosion-proof layer 2 is formed on an inner face 1a of the pipe, a film-like resin tube 3 safe in food hygiene and having chlorine water resistance is inserted, while being contracted or bent, into the pipe after the corrosion-proof layer is formed, and the resin tube 3 is brought into close-contact on the surface of the corrosion-proof layer 2 by heating and pressure expansion or restore processing. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rehabilitating hot water pipes for circulating hot water.

[0002]

2. Description of the Related Art Conventionally, PET (polyethylene terephthalate) has been used as a pipe rehabilitation repair method for water supply pipes.
A method is known in which a thin film resin tube such as a thin film tube is inserted into the tube in a contracted or folded state, and the film tube is brought into close contact with the inner surface of the tube by heating, pressurizing, expanding, or restoring the tube.

In this method, an extremely thin film tube is used as the resin tube for the following reasons. Firstly, since it is intended for pipes with a relatively small diameter, it is necessary to make the resin pipe itself to be thin so that the inner diameter does not decrease after rehabilitation repair. Secondly,
Since the water supply pipe is often bent, it is necessary that the lining pipe itself in the contracted or folded state at the time of insertion has sufficient flexibility. As for the material of the resin pipe, considering its application to water supply pipes for beverages, a material that is safe in terms of food hygiene and has high chlorine resistance, that is, a resin material such as polyethylene terephthalate, polypropylene, polyethylene, polybutene, or ionomer resin. Need to be adopted.

The conventional rehabilitation repair method using a thin film tube will be described with reference to FIG. According to this, as shown in FIG. 2B, the resin pipe R in the contracted or folded state is inserted into the pipe P shown in FIG. Alternatively, by pressurizing the steam, the steam is expanded and finally the resin pipe R is brought into close contact with the inner surface of the pipe P as shown in FIG.

[0005]

The pipe rehabilitated by the conventional method as described above is suitable for circulating low-temperature water, but has the following problems for circulating hot water. That is, since the resin pipe is formed of PET or the like having low heat resistance, water vapor permeates the thin film pipe, and this water vapor causes a problem that the inner surface of the pipe is corroded.

On the other hand, as a method for rehabilitating a water supply pipe having a small diameter, a resin lining method in which a lining agent such as an epoxy resin is conveyed by air flow or static pressure is known, and a pipe rehabilitated by this method is known. When hot water is poured onto the lining layer, the hot water comes into direct contact with the lining layer, so even if the lining layer is completely hardened, harmful components (environmental hormones, etc.) to the human body may dissolve in the hot water, and it may There is a problem that it cannot be applied to the hot water piping of.

The present invention has been proposed in order to cope with such a situation, and is an in-pipe rehabilitation repair method for hot water pipes, which can cope with in-pipe corrosion due to water vapor and distribute it. It is an object of the present invention to provide a method for rehabilitating and repairing hot water pipes in which harmful substances do not flow out into hot water.

[0008]

In order to achieve such an object, the present invention comprises the features of the following claims.

According to the first aspect of the present invention, there is provided a method for rehabilitating hot water pipes for circulating hot water, comprising a step of forming an anticorrosion layer on the inner surface of the pipe, and a film-like resin after the formation of the anticorrosion layer. The method is characterized by including a step of inserting the tube into the tube in a contracted or folded state, and a step of bringing the resin tube into close contact with the inner surface of the anticorrosion layer by heat / pressure expansion or restoration treatment.

The invention according to claim 2 is based on the construction method according to claim 1, and is characterized in that the inner surface of the anticorrosion layer is a non-adhesive surface.

The invention according to claim 3 is based on the construction method according to claim 1 or 2, wherein in the step of forming the anticorrosion layer, a lining agent made of a low-viscosity resin is circulated in the pipe so that the inner surface of the pipe is A feature is that a resin lining film is formed.

The invention according to claim 4 is based on the construction method according to claim 1, characterized in that the material of the resin pipe is selected from polyethylene terephthalate, polypropylene, polyethylene, polybutene, and an ionomer resin.

According to the inventions according to the respective claims,
It has the following effects.

According to the construction method of the first aspect, by forming the anticorrosion layer on the inner surface of the pipe, it is possible to secure the airtightness of the pipe even against corrosion by the steam of hot water. Further, since the film-shaped resin pipe is adhered to the inner surface of the anticorrosion layer, hot water does not come into direct contact with the anticorrosion layer by the resin pipe. Therefore, it is possible to prevent elution of harmful substances into hot water without special selection of the material of the anticorrosion layer itself. By using this resin pipe as a safe material for food hygiene, it can be applied to hot water pipes for drinks.

According to the method of claim 2, since the inner surface of the anticorrosion layer formed on the inner surface of the pipe is a non-adhesive surface, the insertability of the resin pipe to be inserted into the pipe thereafter can be ensured and the pipe having many bent portions can be secured. Also, good workability can be obtained.

According to the method of claim 3, the anticorrosion layer is formed by circulating the lining agent made of a low-viscosity resin in the pipe, so that the anticorrosion layer whose inner surface is a non-adhesive surface is easily formed. be able to.

According to the construction method of claim 4, since the material of the resin pipe is the above-mentioned film which is safe in terms of food hygiene and has chlorine resistance, it can be applied to a hot water supply pipe for heating tap water. .

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view (partial cross-sectional view) showing a hot water pipe subjected to a rehabilitation repair method according to an embodiment of the present invention. The pipe 1 shown in FIG.
The hot water supply pipe (generally, a copper pipe or a steel pipe is used) for circulating the heated hot water is shown. Usually, since it is a pipe connecting the hot water boiler and the hot water storage tank or a pipe for supplying hot water from the hot water storage tank to the supply destination, it has a pipe configuration having a plurality of bent portions 1A and 1B.
When the pipe 1 is rehabilitated, the straight pipe portion is rarely cut off for construction, and the construction section may be divided with a plurality of bent portions left as shown in FIG. Many.

FIG. 1 (b) is an enlarged view of the portion A in FIG. 1 (a). The rehabilitated pipe 1 has a pipe inner surface 1a on which an anticorrosion layer 2 is formed, and a film-shaped resin pipe 3 is in close contact with the inner surface of the anticorrosion layer 2.

FIG. 2 is an explanatory view for explaining the outline of the method for repairing and repairing hot water pipes according to the embodiment of the present invention. FIG. 1A shows a cross section of the pipe 1 related to the rehabilitation repair target. An anticorrosion layer 2 is formed on the pipe 1 as shown in FIG. This anticorrosion layer 2
Is a resin lining film whose surface becomes a non-adhesive surface after formation, and a material having an anticorrosion effect such as an epoxy resin or a urethane resin is adopted.

In FIG. 1C, after forming the anticorrosion layer 2,
The film-shaped resin pipe 3 is inserted into the pipe 1 in a contracted or folded state. As the material of the resin tube 3, polyethylene terephthalate, polypropylene, polyethylene, polybutene, ionomer resin, etc., which are safe from the viewpoint of food hygiene and have chlorine resistance, are used, and polyethylene terephthalate is particularly suitable. Since the anticorrosion layer 2 formed earlier has a non-adhesive surface, no adhesion occurs when the resin pipe 3 is inserted, and smooth insertion is possible even for pipes with many bends. Becomes For the resin pipe 3 inserted in the pipe 1, as shown in FIG.
Pressure expansion or restoration processing is performed. As a result, the resin pipe 3 is brought into close contact with the surface of the anticorrosion layer 2.

FIG. 3 is an explanatory view showing an example of a method of forming the anticorrosion layer 2 in the construction method according to the embodiment of the present invention. This circulates a low-viscosity lining agent in the pipe 1 to be rehabilitated. According to this, the lining agent supplied from the supply unit 4 connected to one end of the pipe 1 is
It is sent to the inside of the pipe 1 by utilizing the pressure from the pressure pump 5, and is circulated in the pipe 1 by the action of the suction portion 6. An opening / closing valve 7 and an air vent 8 are provided at the other end of the pipe 1.

When the lining film which becomes the anticorrosion layer 2 is formed on the inner surface of the pipe 1, the fixing step with warm air is carried out.
By this step, the formed lining film is dried by the hot air to enhance the integration with the inner surface of the tube, and the surface is brought into a non-adhesive state.

In the embodiment of the present invention, the anticorrosion layer 2 is formed so as to cover the inner surface of the pipe with the resin lining in the first step.
Thus, the anticorrosion layer 2 ensures the airtightness of the pipe 1. Therefore, sufficient airtightness of the pipe 1 can be ensured even with respect to corrosion by steam of hot water.

In the second step, since the surface of the formed anticorrosion layer 2 is covered with the thin film of the resin pipe 3,
The surface of the anticorrosion layer 2 does not come into direct contact with the hot water flowing in the pipe, and no harmful substance is eluted from the anticorrosion layer 2 into the hot water.

Since the resin pipe 3 in contact with hot water is made of a material such as polyethylene terephthalate which has no problem in food hygiene and has chlorine resistance, it can be applied to hot water supply for heating tap water. The hot water flowing through this pipe 1 can be used for drinking.

Further, as the material of the anticorrosion layer 2, there is no need to consider food hygiene problems, adverse effects on the human body, etc., and the selection range of materials can be widened, and the construction cost can be reduced by adopting the conventional lining method. It also reduces.

[0028]

According to the method for rehabilitating hot water pipes having such a configuration, it is possible to secure airtightness against hot water pipes used for circulating hot water, even against internal corrosion due to water vapor. It is possible to form a safe pipe in which harmful substances do not flow out into the circulating hot water.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a hot water pipe subjected to a rehabilitation repair method according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating an outline of a rehabilitation repair method according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating a method of forming an anticorrosion layer in the rehabilitation repair method according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating a conventional technique.

[Explanation of symbols]

1 piping 1a Inside of pipe 2 Anticorrosion layer 3 resin lining pipe

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Claims (4)

[Claims] 1. A method for rehabilitating hot water pipes for circulating hot water, comprising the steps of forming an anticorrosion layer on the inner surface of the pipe, and shrinking or folding the film-shaped resin pipe after forming the anticorrosion layer. And a step of bringing the resin tube into close contact with the inner surface of the anticorrosion layer by heating / pressurizing expansion or restoration treatment. 2. The method for rehabilitating hot water pipes according to claim 1, wherein an inner surface of the anticorrosion layer is a non-adhesive surface. 3. The resin-lining film is formed on the inner surface of the pipe by circulating a lining agent made of a low-viscosity resin in the pipe in the step of forming the anticorrosion layer. Rehabilitation repair method for hot water pipes described. 4. The method for rehabilitating hot water pipes according to claim 1, wherein the material of the resin pipe is selected from polyethylene terephthalate, polypropylene, polyethylene, polybutene, and ionomer resin.