JPS6397272A - Formation of rust inhibitive film - Google Patents

Abstract

PURPOSE:To easily and surely form a rust inhibitive film for a piping by fitting a protective member into a valve and cleaning the inside of the piping, then forming a synthetic resin film on the inside surface of the piping and heating the piping by low-voltage current to cure the synthetic resin material. CONSTITUTION:A valve plug 2a of a valve 2 mounted to the water feed piping 1 disposed in a building is removed and the valve inside protective member 3 consisting of the synthetic resin material having elasticity is fitted into a housing 2b of the valve 2. A cleaning liquid is admitted by a pump 5 into the piping 1 through the protective member 3 and is circulated therein to clean the inside of the piping 1. The synthetic resin material 9 for forming the rust inhibitive film is fed into the piping 1 after the cleaning and a spongy coating member 10 is fed thereon. Air is then fed into the piping 1 by an air pump 8 and is changed in the direction so that the coating member 10 flows back and forth. The air is also circulated in the piping 1 by the pump 8 to bring the above-mentioned synthetic resin material into tight contact with the inside surface of the piping. The above-mentioned piping is simultaneously heated by the low voltage current to cure said synthetic resin material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for forming a rust-preventing film on water supply and oil supply pipes and inner surfaces of buildings and other structures.

[Conventional technology]

In water and fuel supply piping installed in buildings and other structures, unclean water such as red water may flow out from the water supply ports. This is because the long-term use of the pipes causes rust to develop on the inner surface of the pipes, causing iron bacterial deposits and the like to flow out. In order to prevent the generation of red water, etc., the inside of the pipe must be cleaned to remove rust and other deposits on the inner surface of the pipe, and then a synthetic resin must be applied to the inner surface of the pipe to form a rust-preventing film.

Hereinafter, a general description will be given of a method of forming this type of rust-preventing film that has been conventionally practiced.

First, as a preparatory work before cleaning, the valves attached to the pipes are removed from the pipes, replaced with valves specifically designed for cleaning and film formation, and the pipes are reinforced during this work. In addition, circulation branch pipes for liquids, etc. will be installed on the piping for each construction area. Additionally, various mechanical equipment such as pumps for construction will be installed.

Conventional methods for cleaning the inside of pipes include blowing dry ballast into the pipes, mixing ballast with water and pumping it, and circulating an aqueous solution of chemicals such as acids using friction stirring using a brush, etc. Methods of dissolving rust, etc., and methods of destroying and removing rust, etc. using ultrasonic waves have been implemented. After applying these methods, clean water is passed through the pipes, and then dry warm air is sent to clean the insides of the pipes.

Conventional methods for forming a film on the inner surface of pipes that have been cleaned include low-viscosity resin liquid coating, high-viscosity resin liquid coating, and phosphoric acid C.
A method of forming a phosphoric acid film using an aqueous solution of a water-soluble substance such as a, and a method of installing an electronic ion regulator have been implemented.

When forming a resin film in Hokkaido film formation, it is necessary to harden the film resin, and the curing methods conventionally include a method of sending hot air into a pipe, a method of sending a hot liquid into a pipe,
A method of flowing a curing agent into a pipe is commonly practiced.

[Problem that the invention seeks to solve]

In the various work processes mentioned above, when valves are removed from piping during preparatory work, the piping may move and be damaged, and it is also necessary to prepare and install valves specifically for construction, which is a complicated process. This also causes an increase in costs.

The method of cleaning the inside of pipes requires a large-capacity pump when using ballast, and there is a risk of damaging pipe bends, joints, etc., and there are various problems such as difficulty in applying it to small diameter pipes. There are many. If friction and agitation are used with a brush or the like, the bent portions and the portions where the pipe diameter changes tend to be insufficiently cleaned, and a great deal of labor is required. Removal methods using ultrasonic waves require special attachment, and the locations where they can be applied are also limited.

In the film forming method, when simply applying a low-viscosity resin, the resin may sag before or during curing, forming an uneven film. On the other hand, when applying a crystalline viscosity resin, it is necessary to move the resin through the piping with high-pressure air at a specific temperature, which increases the size of the equipment and costs. Furthermore, the application range of forming a phosphoric acid film using a water-soluble substance such as Ca phosphate is subject to various restrictions, and the installation of an electronic ion regulator is also a special procedure that is not common.

In the method of curing the film, when sending hot air or hot liquid into the pipe, there are problems such as the need for a large amount of pumps in long pipes to prevent the temperature of the hot air or hot liquid from dropping and to overcome flow resistance. There are many points. Furthermore, when flowing a hardening agent, there are various restrictions such as the selection of the resin to be used and the action of the hardening agent.

The present invention overcomes the above-mentioned problems, eliminates the need to remove or replace the entire valve during preparation work, facilitates cleaning work inside the piping without any restrictions, and facilitates and reliably forms and cures the resin film. It is an object of the present invention to provide a method for forming a rust-preventing film inside piping, which can be carried out at low cost.

[Means for solving problems]

The means of the present invention for solving the above-mentioned problems is a method of cleaning a water supply pipe installed in a building to form a rust-preventing film on the inner surface, by removing the valve body of a valve attached to the pipe. A valve internal protection member made of an elastic synthetic resin material is fitted into the valve housing, and a cleaning liquid is circulated by flowing into the pipe through the protection member using a pump to clean the inside of the pipe.After cleaning, the inside of the pipe is cleaned. A synthetic resin material for forming a rust-preventive film is inserted into the pipe, and air is circulated within the pipe using an air pump to bring the synthetic resin material into close contact with the inner surface of the pipe. At the same time, the pipe is heated with a low electric current, and the synthetic resin material is heated by a low electric current. This is a method for forming a rust-preventing film characterized by curing a resin material.

[For production]

Since the cleaning liquid is circulated through the valve protection member and the synthetic resin material is inserted into the piping, cleaning and film formation are possible without damaging the inner surface of the valve housing or adhering the synthetic resin. Since the piping is heated by voltage and current, curing of the synthetic resin film is extremely simple and easy. Further, since there is no need to remove the entire valve from the piping, the work is easy and the piping will not be damaged.

〔Example〕

Next, the present invention will be described by way of examples with reference to the drawings. Figure 1 (A), (B), (C), (D)
2 is a sectional view of the apparatus for detailed explanation of the present invention, and FIG. 2 is a partially enlarged sectional view of FIG. 1 (D'). The valve 2 attached to the pipe 1 has a valve body 2a and a housing 2b, but in order to carry out the present invention, the valve body 2 is installed as shown in (A).
a is removed, and the housing 2b is connected to the pipe 1. Next, as shown in (B), a valve internal protection member 3 made of an elastic synthetic resin material is fitted into the housing 2b of the valve 2. This protective member 3 has a hollow part 3a inside, and the hollow part 3a has an outer opening 3b and an inner opening 3c.One end of a cleaning hose 4 is connected to the outer opening, and the inner opening 3c has a pipe 1. Open towards. As shown in (c), the other end of the cleaning hose 4 is connected to a cleaning liquid pump 5,
A cleaning liquid circulation hose 6 connects the open lower end of the portion of the piping 1 to be cleaned and coated to the pump 5. In this state, the pump 5 pumps cleaning liquid (acidic liquid, etc.) to the hoses 5 and 6.
The water is then circulated back and forth within the pipe 1 as shown by the arrows to remove rust, scale, etc. from the pipe 1 and clean it. After cleaning, the cleaning liquid is drained, the inside of the pipe 1 is rewashed with clean water, and then dried. Drying is done by natural drying or by supplying dry air. next,(
As shown in D), the cleaning liquid pump 5 is replaced with an air pump 8, a synthetic resin 9 for film formation is injected into the pipe 1, and a sponge-like application member 10 is introduced. The application member 10 is in contact with the inner circumference of the pipe and has a size that allows it to move in the axial direction of the pipe 10. Activate the air pump 8, and the hose 4,
Air is sent into the pipe 1 through the pipe 1, and its direction is changed to cause the application member 10 to reciprocate as shown by arrow R.

As a result, the resin 9 is uniformly applied to the inner surface of the pipe 1 to form a resin film. The pipe 1 has a low voltage current heating means 11
is provided, and heats the pipe 1 during resin application to harden the resin film and fix it on the inner surface of the pipe 1.

As shown in FIG.
When the resin 9 is reciprocated as shown in the figure, the resin 9 existing in the pipe 1 in a non-uniform state forms a uniform resin film 9a. The low-voltage current heating means 11 is composed of a transformer lla and a cable llb, and the voltage is stepped down by the transformer lla, and a low-voltage current is passed through the cable llb to the heating area of the pipe 1 to heat it. This operation may be repeated as necessary.

In the embodiment described above, the resin 9 was applied to the inner surface of the pipe 1 using the coating member 10. For example, when the pipe diameter is large, a tube made of a flexible synthetic resin film that hardens under certain conditions is passed through the pipe. This tube may be expanded with air and brought into close contact with the inner surface of the piping, and a rust-preventing film may be formed on the inner surface of the piping by means of low voltage current heating means.

Figure 3 is a schematic diagram when the present invention is applied to a building, an apartment, etc., where water stored in a water tank 21 is supplied from a water pipe 20 to pipes 1, 1°, 1'' on each floor. For example, the pump 5 (8) and hose 4 are connected to the piping l on the top floor.
Cleaning and film formation are carried out in step 6.

〔Effect of the invention〕

As explained above, when forming a rust-preventing film on the inner surface of a pipe, the present invention involves fitting a protective member into the valve, cleaning the inside of the pipe, and then forming a synthetic resin film on the inner surface of the pipe.
Since the pipes are heated with low voltage current to harden the synthetic resin film and form a rust-preventing film on the pipes, there is no need to remove or replace the entire valve, therefore there is no damage to the pipes, and cleaning work is simplified. It is easy and has no restrictions, and furthermore, the formation and effect of the resin film can be easily and reliably carried out, and furthermore, it has the advantage that it can be carried out at a low cost that requires special or large-scale equipment.

[Brief explanation of the drawing]

Figures 1 (A), (B), (C), and (D) are sectional views of the device for detailed explanation of the present invention; Figure 2 is a partially enlarged sectional view of Figure 1 (D); FIG. 3 is a schematic diagram of an application example of the present invention. 1... Piping, 2... Valve, 3... Valve internal protection member, 4... Cleaning hose, 5... Cleaning liquid pump , 6... Circulation hose, 7... Opening, 8... Air pump, 9... Synthetic resin, 9a... Film, 10... . . . Application member, 11 . . . Low voltage current heating means.

Claims (1)

[Claims] In a method of cleaning water supply pipes installed in a building to form a rust-preventing film on the inner surface, the valve body of a valve attached to the pipe is removed and the inside of the valve housing is made of an elastic synthetic resin material. A protective member inside the valve is fitted, and a cleaning liquid is pumped into the pipe through the protective member and circulated to clean the inside of the pipe. After cleaning, a synthetic resin material for forming a rust-preventing film is introduced into the pipe. The prevention method is characterized in that air is circulated within the piping by an air pump to bring the synthetic resin material into close contact with the inner surface of the piping, and at the same time the piping is heated with a low electric current to harden the synthetic resin material. Rust film formation method.