JPS641592Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multiple cladding tube used for piping, pillars, etc.

[Conventional technology]

Conventionally, steel pipes used for piping, pillars, etc. are: (1) pipes coated with an anti-corrosion layer, (2) pipes with mortar etc. further coated on the anti-corrosion layer, and (3) steel pipes coated with an anti-corrosion layer. There are double pipes in which mortar or the like is inserted between the pipe and the outer pipe, and each type of pipe is in practical use.

[The problem that the idea attempts to solve]

Since the pipe of type (1) above simply has an anti-corrosion layer on its surface, it has the disadvantage that the pipe body is easily damaged during transportation, installation, etc.
However, if the mortar peels off due to impact or contact with obstacles in the ground, the same problem as (1) will occur, and when applying mortar lining, a formwork is required, making manufacturing time-consuming. There are drawbacks such as this. Furthermore, the type (3) had problems such as the outer tube having a thick wall and being uneconomical from the standpoint of protecting the tube body.

This invention was devised to solve the above-mentioned problems with conventional pipes, and aims to provide a multi-clad pipe that is easy to manufacture, maintains its anti-corrosion performance over a long period of time, and is lightweight. It is.

[Means to solve the problem]

The multi-clad tube according to the present invention covers a main tube having anti-corrosion layers on the inner and outer surfaces with an outer tube having spiral ribs on the inner surface and having an inner diameter larger than the outer diameter of the main tube,
The gap formed between the outer tube and the main tube is filled with mortar and hardened to integrate the outer tube and the main tube.

[Effect]

Although the outer tube used in this invention is unexpectedly thin, it has spiral ribs on the inside, so it not only does not deform under pressure applied from the outside, but also has mortar. It can sufficiently withstand injection pressure during injection.

[Example of idea]

FIG. 1 shows an embodiment of a multiple cladding tube according to the present invention, in which a is a vertical cross-sectional view and b is a cross-sectional view taken along line a-a'. In the figure, anti-corrosion layer B-1 on the inner and outer surfaces of 1,
B-2 main pipe 2 has an inner diameter larger than the outer diameter of main pipe 1, a spiral type with a smooth outer surface and a protruding rib R on the inner surface, and a thin wall thickness (e.g. 1 mm).
The outer tube 3 is mortar filled in the gap formed between the main tube 1 and the outer tube 2.

In manufacturing the multi-clad tube of the present invention, the main tube 1 is inserted into the outer tube 2 concentrically with the outer tube 2, and the gap formed between the two is filled with mortar 3, which is then hardened. .

At this time, the ribs R on the inner surface of the outer tube 2 are
The outer tube 2 acts as a reinforcing material against the tensile force caused by the injection pressure, and can maintain sufficient strength as a formwork even though the outer tube 2 is thin. After the mortar 3 hardens, the outer tube 2 and the mortar 3 are completely integrated via the ribs R of the outer tube 2.

When using a multi-clad pipe configured as described above, for example, as a propulsion pipe, it is necessary to prevent damage to the main pipe 1 and anti-corrosion layer B-2 during propulsion due to ground properties (ground with many breccias, etc.) and obstacles. Thus, the outer tube 2 and the mortar 3 are integrally protected. Further, the outer tube 2 is not displaced in the tube axis direction due to the frictional force on the circumferential surface of the tube that occurs during propulsion.

Furthermore, in the case of buried pipes, when transporting them,
Main pipe 1 and corrosion protection layer B-2 during installation, backfilling, etc.
damage can be prevented.

When used on architectural pillars, fireproof covering material (fireproof mortar, etc.) and decorative board (exterior) are required.
Traditionally, formwork was used for cladding work, and the formwork was removed and decorative panels were installed. Also, when cladding pipes were used as the pillars of offshore structures, conventionally the same method was used after the pillars were installed. Mortar is poured on-site using a formwork, but according to the present invention, the outer tube also serves as the formwork, which simplifies the work process even in the above-mentioned cases.

Note that the multiple cladding tube of the present invention can be manufactured in a factory or on-site depending on the situation.

Next, a comparison will be made between a conventional armored steel pipe and an embodiment of the multiple cladding pipe of the present invention (in the case of covering a 1000A steel pipe). In conventional armored steel pipes, the main pipe (steel pipe)
Asphalt vinylon cloth was wrapped around the outer surface of the main pipe (steel pipe) to a thickness of 6 mm, and mortar was filled between the outer surface of the main pipe (steel pipe) and the outer pipe with a wall thickness of 6.0 mm. wrapped with asphalt vinylon cloth to a thickness of 4 mm or coated with 0.3 mm of tar epoxy paint, and between an outer tube of 1.0 mm wall thickness and having ribs with a protrusion height of 3.0 mm and a width of 7 to 8 mm on the inner surface. was filled with mortar.

When the two obtained in this way were compared, it was found that the one according to the present invention had an effect equal to or better than that of the conventional one. That is, according to the present invention, the wall thickness of the outer tube is reduced to 1/6 of that of the conventional one, and a cladding tube that is firmly integrated can be obtained.

[Effect of idea]

As described above, the multi-clad pipe according to the present invention is: (1) Compared to conventional double-layer steel pipes, the outer pipe also serves as a formwork and is extremely lightweight, so it is easy to handle; Moreover, since the manufacturing process is simplified, costs can be reduced.

(2) Items that were conventionally manufactured on site can now be manufactured in a factory by preventing damage during transportation, thereby improving quality.

(3) Ribs on the inner surface of the outer tube integrate the filling material such as mortar and the outer tube, eliminating displacement of the outer tube during propulsion and preventing damage to the main tube and anti-corrosion layer during propulsion and burial. This makes it possible to maintain long-term anti-corrosion performance.

It is possible to achieve great effects such as:

[Brief explanation of drawings]

FIG. 1 shows an embodiment of a multi-clad tube according to the present invention, in which a is a vertical cross section and b is a cross section along a-a'. 1: Main pipe, 2: Outer pipe, 3: Mortar, B-1,
B-2: Anticorrosion layer, R: Rib.

Claims (1)

[Scope of utility model registration request] A main pipe having anti-corrosion layers on the inner and outer surfaces is covered with an outer pipe having a spiral rib on the inner surface and an inner diameter larger than the outer diameter of the main pipe, and the gap formed between the outer pipe and the main pipe is A multi-clad pipe characterized by being filled with mortar and hardened to form an integrated structure.