JPS6229753Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an anti-corrosion structure, and more particularly to an anti-corrosion structure useful for protecting an anti-corrosion layer formed on the outer periphery of a buried cast iron pipe or the like.

[Conventional technology]

Conventionally, the outer periphery of cast iron pipes, etc. buried in the soil has been coated with polyethylene film, vinyl chloride film, or an adhesive on top of the anticorrosive layer formed on the outer periphery of the cast iron pipe, with the aim of preventing destruction of the anticorrosive layer in the soil. It is widely practiced to wrap a film coated with

[Problems with conventional technology]

However, although the above-mentioned protective films for anti-corrosion layers are effective in preventing destruction due to input earth and sand when pipes are backfilled into the soil, they are not effective against pressure generated by earth pressure etc. after backfilling. You can't expect much protection from it.

In other words, when there is a change in earth pressure due to ground movement or vibration, the protective film deforms together with the corrosion protection layer and becomes wrinkles or folds, making it impossible to stop the deformation of the corrosion protection layer. It wasn't enough to make the effect permanent.

[Problems solved by invention]

In view of the above, this idea was developed to provide a corrosion protection layer that can exert its protective function over a long period of time without causing wrinkles, folds, or other deformation along with the corrosion protection layer, even if there are changes in the earth pressure around the buried pipe. This was done for the purpose of providing structure.

[Technology to solve problems]

That is, in the anticorrosion structure of this invention, a protective sheet or tape for the anticorrosion layer, which has a fluid mastic layer on at least one side of a sheet or tape-like base material, covers the anticorrosion layer formed on the outer peripheral surface of the steel pipe. It is wound inside.

〔Example〕

Next, this invention will be explained using examples.

Figure 1 is an enlarged sectional view of the main parts of an embodiment of this invention.
FIG. 3 is a sectional view of an embodiment of this invention, and FIG. 4 is an enlarged sectional view of the embodiment.

The anti-corrosion structure of this invention consists of a protective sheet or tape 1 for an anti-corrosion layer in which a fluid mastic layer 3 is provided on at least one side 2A of a sheet or tape-like base material 2 on an anti-corrosion layer 4 formed on the outer peripheral surface of a steel pipe 5.
is wound with the flowable mastic layer 3 inside.

In the above, the protective sheet or tape 1 for the anticorrosion layer is a sheet or tape of about 0.1 to 3 mm thick made of plastic polymer such as polyethylene, vinyl chloride, polypropylene, polyester, or nylon, or a sheet or tape of about 0.1 to 3 mm thick made of aluminum, stainless steel, etc. Metal foil of about 1 mm, or rubber sheet of about 0.2 to 3 mm thick of synthetic rubber such as ethylene-propylene-diene terpolymer rubber, chloroprene rubber, butyl rubber, styrene-butadiene rubber, and/or natural rubber, etc. On one side 2A of the base material 2, a substance with a low molecular weight and having lubricity, or a substance that exhibits lubricity when heated, such as silicone, lubricant, wax, grease, glycerin, oil, asphalt, low-molecular polyisobutylene, and rubber with excellent fluidity. And/or a fluid mastic layer 3 made of synthetic resin or adhesive is provided.

In the above embodiment, the flowable mastic layer 3 is provided on one side of the base material 2, but it may be provided on both sides as shown in FIG.

[Effect]

The protective sheet or tape 1 for the anticorrosive layer of this invention is obtained by wrapping an anticorrosive adhesive tape 6 around the outer periphery of a tube 5 on which an anticorrosive primer layer 4 made of tar, epoxy, etc. is provided, and then wrapping it over the tube 5. Ru. Note that the adhesive tape 6 is not necessarily necessary, and the protective sheet for the anticorrosion layer or the tape 1 may be wound directly onto the thick anticorrosion primer layer 4.

Even if the ground 7 changes after the pipe 5 is backfilled in this state, the fluid mastic layer 3 is formed on one or both sides of the anti-corrosion protective sheet or tape 1. acts as a lubricant between the anti-corrosion layer 4 or the adhesive tape 6, or between the ground 7, disperses earth pressure or makes it slippery, and prevents shear force from being transmitted to the anti-corrosion layer 4. This prevents wrinkles and folds from forming.

The anti-corrosion protective sheet or tape 1 used in this invention has the above-mentioned lubricating effect, so even if it is used on other pipes such as plastic pipes, the shearing force due to earth pressure will not be directly applied to the pipe. Therefore, it is possible to prevent internal stress from occurring in the tube wall due to shearing.

〔effect〕

Since this invention is constructed as described above, it is possible to prevent destruction of the corrosion protection layer 4 due to soil injection when backfilling the pipe with the corrosion protection layer protective sheet or tape 1 wound on the corrosion protection layer 4. In addition, the fluid mastic layer 3 disperses the force of earth pressure,
Alternatively, to make it slippery, shear force is prevented from being applied to the anti-corrosion layer 4, and the anti-corrosion layer is completely prevented from deforming into wrinkles or folds, making it possible to maintain the anti-corrosion effect over a long period of time. It can be done.

[Brief explanation of the drawing]

Figure 1 is an enlarged sectional view of the main parts of an embodiment of this invention.
FIG. 2 is a sectional view of another embodiment, FIG. 3 is a sectional view of the embodiment, and FIG. 4 is an enlarged sectional view of the main part of the embodiment. 1...Protective sheet or tape for anti-corrosion layer, 2
... Base material, 3 ... Fluid mastic layer, 4 ... Anticorrosion layer, 5 ... Steel pipe, 6 ... Anticorrosion adhesive tape, 7 ...
…ground.

Claims (1)

[Scope of utility model registration request] Corrosion protection in which a protective sheet or tape for corrosion protection layer, which has a fluid mastic layer on at least one side of a sheet or tape-like base material, is wound on the corrosion protection layer formed on the outer peripheral surface of the steel pipe with the mastic layer inside. structure.