JPH0228318Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field] This invention relates to a heat-shrinkable corrosion-proofing material used for live pipe branching of gas piping, and more specifically for live pipe branching in which branch pipes are newly installed at work sites. To provide a corrosion-proofing coating that can be applied to parts with high quality and in a short time.

[Prior art]

The hot tap method is a method for installing branch pipes on pipelines used for liquid transportation without interrupting the transportation of fluids such as gas flowing through the pipes. There is.

After construction is carried out in accordance with this method, the live pipe branch inevitably has an irregularly shaped part with a complicated shape. This kind of piping is usually treated with anti-corrosion treatment on its outer surface, and anti-corrosion measures have conventionally been taken such as wrapping anti-corrosion tape around the branching portions of the live pipes as well.

However, although this tape method is a simple method, there are many difficulties when actually applying tape to curved parts of pipes, irregularities, or irregularly-shaped parts with branches. corrosion protection coating defects.

One way to improve this problem is to wrap petrolatum anticorrosion tape. 1st
The second diagram showing the A-A cross section in Figures and Figure 1.
To explain using the drawings, in this case, 1 indicates a main pipe, and a branch pipe 3 branched by the live pipe construction method extends from the main pipe. 2 is the part sealed with a cap formed using the live pipe construction method.

Since the petrolatum anticorrosive tape 4 has plasticity at room temperature, it easily adapts to irregularly shaped portions such as branched portions or uneven portions and is easy to wrap around the tape. Generally, a protective tape 5 made of polyethylene, vinyl chloride, etc. is wound around the upper layer for reinforcement.

However, this petrolatum anticorrosive tape 4
Because it has not lost its plasticity even after construction, it is easily deformed.For example, after being buried underground, it can easily deform due to earth pressure or pressure from some kind of protrusion, which can cause defects. There are many. Also, even if we look only at the time of construction, anti-corrosion tape 4
There is a problem in that the winding or pasting work is relatively time-consuming.

Another method is to apply a room-temperature curing mastic resin to form the resin 6, as shown in FIG. 3 and FIG. 4, which shows the B-B cross section in FIG. . Note that FIGS. 3 and 4 are cross-sectional views explaining the same situation as in FIGS. 1 and 2.

However, with this method, it is not only difficult to uniformly apply resin to irregularly shaped parts without creating pinholes, but it also takes time for the resin to harden, so it is necessary to quickly backfill with buried pipes. The problem is that it cannot be used in certain cases.

There is also a covering material made by bonding a heat-shrinkable sheet with cylindrical protrusions formed from the same heat-shrinkable material; However, there remains the inconvenience that it is difficult to achieve a sufficient coating effect and additional auxiliary means are required.

[Purpose of invention]

The present invention provides a corrosion-proof coating for a newly installed live pipe branch part of a pipe with high quality and in a short time.

[Summary of the idea]

The present invention has been developed to achieve the above-mentioned objectives: 1. It can be easily and quickly applied to irregularly shaped parts and branching parts with large irregularities at the construction site; 2. Pinholes and other defects will not occur in the anticorrosive coating after construction. 3. No curing time required for hardening of the coating material, etc. 4. The anticorrosive coating after construction has the strength to withstand earth pressure during burial, etc. This was developed after intensive study of a corrosion-resistant coating that satisfies the following requirements. .

That is, in the present invention, when a base sheet made of heat-shrinkable rubber or plastic provided with a cap-shaped bulge is formed into a cylindrical body, the cylindrical body has a cylindrical body with an angle of approximately 180° with respect to the cap-shaped bulge. This anti-corrosion protection for active pipe branch parts of piping is provided with a cap-shaped bulge made of heat-shrinkable rubber or plastic and provided with a pipe part for branch pipes at the position of a base material sheet.

The base sheet of heat-shrinkable rubber or plastic can be any material that exhibits an anticorrosive effect, but specifically, for example, polyethylene,
Sheets made of polyvinyl chloride, polypropylene, ethylene-vinyl acetate copolymer, ethylene rubber, propylene rubber, butyl rubber, etc. are the most readily available.
In addition, although general materials are easy to use, it is of course possible to use partially modified products of these materials or other synthetic resin sheets to obtain other special properties. As for the heat shrinkage function imparted to this synthetic resin sheet, although a uniaxial heat shrinkage function may exhibit some effect, it is preferable to use a heat shrinkage function that shrinks biaxially.

A heat-shrinkable rubber or plastic base sheet is provided with a cap-shaped bulge, and when the base sheet is formed into a cylindrical body, the base sheet is at approximately 180° with respect to the cap-shaped bulge of the cylindrical body. The reason why a cap-shaped bulge made of heat-shrinkable rubber or plastic with a pipe section for a branch pipe is provided at the position is that the corrosion protection of the present invention is aimed at preventing corrosion of the live pipe branch part of piping. Because it is a food ingredient.

In the live pipe construction method for this type of piping, as shown in the drawings mentioned below, there is a protruding part sealed with a cap etc. on a part of the main pipe (usually the upper side), and the protruding part is placed at a position approximately 180 degrees (usually On the lower side) a protruding part with a branch pipe is necessarily provided. This is because a hole is drilled into the main pipe from the upper protrusion using a drilling machine or the like.

The corrosion-proofing material of the present invention has a suitable shape that allows the corrosion-proofing material to be brought into close contact with the live pipe branch portion of such piping.

In order to form a cap-shaped bulge in the base sheet, in the case of a small scale, it is possible to form the cap-shaped part by deep drawing during or before or after the sheet stretching process. If this method is difficult to use, a separately prepared cap-shaped portion may be bonded to the opening of a stretched heat-shrinkable sheet with an opening, using an appropriate adhesive or the like. It's okay.

In such a case, the materials of the heat-shrinkable sheet, the cap-shaped part, and the pipe for the branching part can be changed as necessary, or in some cases, the heat-shrinkable sheet and the cap-shaped part can be joined in advance. It is also possible to heat-seal the plastic sheet and the cap-like part during the heat-shrinking operation.

As mentioned above, when carrying out anti-corrosion work on live pipe branches, it is generally possible to predict the diameter of the target pipe or the construction conditions, so it is necessary to prepare an appropriate anti-corrosion material. I can and
Furthermore, even if the shape is not as expected, it is an anti-corrosion material that can be adapted to suit the situation by combining heat-shrinkable rubber or plastic sheet with the cap-like part.

[Example of idea]

The anticorrosive material of the present invention will be specifically described below with reference to Examples.

The fifth is a partial perspective view of a live pipe branch constructed using the anticorrosive material of the present invention. The figure shows a state in which a heat-shrinkable plastic sheet 7 is set in a portion 2 sealed with a cap provided on the main pipe 1.

The heat-shrinkable plastic sheet 7 has a sheet portion 8 covering the active tube branch body, a cap-shaped bulge 9, and a cap-shaped bulge 13 having a branch pipe pipe portion 10 extending from the sheet opening. This branch pipe 10 generally has a cap-shaped bulge 13.
or a part thereof.

The cap-shaped bulging portion 13 may be formed from a separate sheet and joined to the sheet portion 8 in this invention, but is preferably formed by deep drawing the sheet portion 8.

When performing construction using corrosion-proofing material having such a structure, the branching pipe 10 of the corrosion-proofing material is passed through the branch pipe 3 in advance, and after the branching work is completed, the sheet portion 8 is wound around the main pipe 1 while the bulging portion 9, There are bulges 9 and 13 in the part 2 where 13 is sealed with a cap.
The sheets are fitted one after another and the joints 12 of the sheets are adhered and set. Next, it is heated with a suitable heating means such as a hand burner and is fitted onto the connecting body.

The simplest way to connect the sheets to each other is to overlap the sheet portions 8, but for example, the end portions of the sheets extending from the top (or bottom) may be bifurcated, and correspondingly the bottom (or If the ends of the sheet wound to be polymerized from above are made into a three-pronged shape and held in each of the two ends, a strong temporary fixing can be achieved.

In addition, the above explanation is specifically illustrated in the sixth section.
The difference between the two figures is that the joint is located on the branch pipe side and on the opposite side.

[Effect of idea]

As explained above, the heat-shrinkable base sheet of the present invention has two cap-shaped bulges corresponding to the two protrusions such as caps at the live pipe branch of the main pipe, and one cap-shaped bulge. Since the section has a pipe section for branch pipes that covers branch pipes branching from the main pipe, the heat-shrinkable base material sheet described above can be applied once to prevent corrosion of complex-shaped live pipe branch sections of main pipes. The construction can be completed in about 30 minutes, which has the effect of improving construction efficiency and speeding up backfilling. In addition, since the two cap-shaped protrusions provided on the heat-shrinkable base material sheet are shaped to match the two protrusions such as caps at the live pipe branch of the main pipe, the complexity of the live pipe branch is It adapts well to various shapes, does not require the high degree of skill required by conventional methods, makes work at construction sites easier, and has the effect of allowing defect-free, high-quality, highly reliable anti-corrosion coatings to be installed on-site.

[Brief explanation of the drawing]

Figures 1 to 4 show corrosion protection construction using the conventional method. Figure 1 is a partial sectional view, and Figure 2 is A--A in Figure 1.
Figure 3 is a cross-sectional view taken along line A, Figure 3 is another partial cross-sectional view, Figure 4 is a cross-sectional view taken along line B-B in Figure 3, and Figures 5 to 7 show examples of construction using the anticorrosive material of the present invention. FIG. 1... Main pipe, 2... Portion sealed with cap, 3... Branch pipe, 7... Heat-shrinkable plastic sheet, 8... Sheet part, 9... Cap-shaped bulging part, 10... For branch pipe pipe.

Claims (1)

[Scope of Claim for Utility Model Registration] When a base sheet made of heat-shrinkable rubber or plastic on which a cap-shaped bulge is formed into a cylindrical body, approximately
A corrosion-proofing material for a branch part of a live pipe of piping, characterized in that a cap-shaped bulge part made of heat-shrinkable rubber or plastic and provided with a pipe part for a branch pipe is provided at a position of 180 degrees of the base sheet.