JPH0219668Y2 - - Google Patents

Description

[Detailed description of the invention] Purpose of the invention (industrial application field) The present invention is intended for use with rod-shaped objects with circular cross sections such as pipes and communication cables (these are collectively referred to as pipes in this specification). This invention relates to a sealing device installed between the surrounding pipe or a hole in a structure. To explain in more detail, the present invention is effective when a substantial double-pipe structure is used, such as burying the main pipe using a sheath pipe or penetrating pipes into a circular hole in the structure. The present invention relates to a sealing device for buried pipes that fills the gap between the pipes and the holes around them to position and protect the pipes and maintain an airtight/watertight structure.

(Prior art) When underground pipes are buried underground to transport gas, oil, water, cold/hot water, steam, etc. for district heating and cooling, when it is necessary to cross a river, road, railway, etc., the main pipe is It is well known that for protection, a double-pipe construction method is used in which a sheath pipe is installed in advance and the main pipe is drawn into it.

At this time, there are problems such as rust caused by stray current caused by contact between the main pipe and sheath pipe, and the inflow of earth and sand from the gap between the main pipe and sheath pipe, so electrical insulation is required between the two pipes. It is required to install a sealing device.

Conventional sealing devices of this type have used materials such as blown asphalt and room-temperature vulcanized rubber, but these all involve installing a mold at the end of the pipe and injecting liquid sealing material into it. ,
Not only is the work cumbersome, but a large amount of filler is required, resulting in high costs.

Therefore, as shown in FIG. 3, a structure is adopted in which two disk-shaped rubber rings 101, 102 facing each other are sandwiched between flanges 103 from both sides, and by tightening bolts 104, the rubber rings 101, 102 are moved in the radial direction. A tube end sealing device has been proposed that completely maintains airtightness by sealing the space between the main tube 105 and the sheath tube 106 (Utility Model Application No. 110, 820).

In the case of this tube end sealing device, rubber 101, 10
Utilizing the excellent electrical insulation, elasticity, and stretchability of the main pipe 105 and the sheath pipe 106, a main pipe is installed in the center of the sheath pipe 106 to completely insulate and seal the main pipe 105 and the sheath pipe 106 and absorb vibrations. Tube 105 may be secured tightly. Moreover, this sealing device allows the main pipe 105 to be attached with only simple work, so the construction work can be streamlined and it is extremely economical in terms of price.

(Problem to be solved by the invention) However, in the case of this sealing device, the sealing performance is limited to the plate-shaped rubber 1 due to the pinching of the flange 103.
01, 102, the existence of the flange 103 suppresses the deformation of the rubber 101, 102, and there is a problem that the amount of eccentricity cannot be increased as much.

That is, since airtightness is obtained by the elasticity of the rubber rings 101 and 102 that protrude inwardly and outwardly from the flange 103, the amount of eccentricity can only be reduced by the deformation of the rubber in the portions protruding from the flange 103. Since adjustment is possible, when used in abnormal conditions such as in places where uneven ground subsidence occurs or when installed at an angle, the sheath pipe and main pipe come into direct contact via the flange 103, reducing stray current and vibration. There is a risk that this will be communicated to the main office.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a sealing device for tubes that has a substantially double-tube structure, which is inexpensive and simple, and has a larger eccentricity than conventional sealing devices.

Structure of the Invention (Means for Solving Problems) In order to achieve the above object, the sealing device for pipes of the present invention penetrates through a sheath pipe or a hole in a structure to form a substantial double pipe structure. The liquid is enclosed in a ring-shaped elastomer tube that fits into the buried pipes and expands when the liquid is press-fitted to fill the gap between the pipes and the sheath pipe, causing the liquid to lose its fluidity. A liquid fixing material is continuously arranged, and the liquid press-ined for expansion of the tube is adsorbed and fixed by the liquid fixing material, so that the tube and the filling liquid are maintained as an integral elastic body.

(Example) The configuration of the present invention will be described in detail below based on an example shown in the drawings.

The sealing device of the present invention has a liquid fixing material 2 continuously arranged inside a ring-shaped elastomer tube 1. By pressurizing liquid into the tube 1, the tube 1 is expanded and the sheath tube is expanded. The gap S between the pipe 3 and the main pipe 4 is filled and sealed.

The tube 1 is generally integrally molded in a ring shape from an elastomer material such as rubber or elastic plastic, and has at least one air bleed port 5 and at least one liquid inlet 6, and is capable of injecting liquid while removing air. The device is designed to be inflated.
This tube 1 consists of an inner tube 4 and an outer sheath tube 3.
In order to bring them into close contact with each other, it is preferably formed in a cross-sectional shape, for example, an oval shape, so that the contact area can be made as large as possible.

Inside the tube 1, a liquid fixing material 2 is disposed almost continuously around the entire circumference. This liquid fixing material 2 is usually attached to a support such as fibers or foam to form a seal or film, or the liquid fixing material 2 itself is formed into a fiber shape and arranged continuously throughout the tube. However, it is also possible to encapsulate the powder in a powder state and arrange it continuously and uniformly throughout the tube by stirring with the injected liquid.

As the liquid fixing material, any substance that causes the fluidity of the liquid to be lost can be used, and among them, it is preferable to use hydrogel-forming substances, and in particular, it is most preferable to use water-absorbing polymers that have excellent water absorption and water retention properties. be.

As the water-absorbing polymer, any known polymer that generally has a structure in which a water-soluble polymer is slightly crosslinked to make it insolubilized may be used. for example,
Examples of the water-absorbing polymer include modified cellulose, modified starch, cellulose-acrylic graft, starch-acrylic graft, polyacrylamide and polyacrylate, vinyl acetate-acrylate copolymer, and polyoxyethylene. There are other polymers such as non-ionic ones such as polyvinylpyrrolidone and polyvinyl alcohol, and polysulfonic acid-based ones such as polystyrene sulfonic acid and poly-2-acrylamido-2-methylpropanesulfonic acid. Any polymer can be used. However, it is particularly preferable to use one that has excellent water retention properties.
The amount of water-absorbing polymer filled must be at least sufficient to absorb the entire amount of liquid that fills the tube during expansion. Therefore, in order to eliminate the bulk of the liquid fixing material 2, it is preferable to use a water-absorbing polymer that absorbs at least 100 times its own weight of liquid.

As the other liquid fixing material 2, it is also possible to use a substance that envelops the liquid and forms a jelly-like gel, such as a gelling agent such as gelatin or gum arabic. It is also possible to use a substance that envelops oil to form a jelly-like gel, such as a gelling agent such as a condensation reaction product of D-sorbitol and benzaldehyde.

The liquid to be press-fitted into the tube 1 includes water,
Although oil or any other liquid can be used,
The use of water is most preferred as it is readily available everywhere and at low cost. Of course, in addition to regular water,
Although it is possible to use water with special ingredients such as physiological saline or electrolyte solution, it is not only expensive, but also has no effect on the water absorption performance of the water absorbing polymer and has little effect on sealing properties. Not effective.

The above-mentioned liquid fixing material 2 is usually sealed in the bag when the tube 1 is molded. For example, the illustrated tube 1 is integrally molded into a U-shaped cross section except for one side edge, and then air and liquid fixing material are put inside and inflated while the remaining one side edge is covered. It is welded and molded. Therefore, after fitting the tube 1 into the main pipe 4 at the work site, the tube 1 is expanded by pressurizing liquid such as water through the injection port 6 at the bottom, and the sheath pipe 3 and the main pipe 4 are inflated. The gap S between the two can be closed. At this time, water is injected from the injection port 6 at the bottom of the tube while removing the air inside the tube from the air bleed port 5 at the top, and after the air has been completely removed, close the air bleed port 5 to increase the water pressure inside the tube. , inflating the tube 1 radially.
For water injection, the outer and inner surfaces of tube 1 are connected to main pipe 4.
and the sheath tube 3 respectively, and the water inlet 6 is closed.
The water injected into the tube 1 is absorbed by the liquid fixing material/water-absorbing polymer 2 and loses its fluidity.
Together with this, the elastic body is integrally constructed. Normally, the water in the elastomeric tube 1 flows due to external loads and cannot prevent the tube 1 from being crushed, but when it is fixed by the liquid fixing material 2, it exhibits appropriate elasticity and low resistance. Prevent the tube 1 from being crushed.

Therefore, while the main tube 4 is elastically supported by the sheath tube 3 via the tube 1, the main tube 4 is electrically and vibrationally supported by the sheath tube 3.
It is completely insulated and firmly fixed to the center of the sheath tube 3.

Note that this sealing device can be used not only for construction of double-walled piping using the sheath pipe 3, but also for any structure such as the wall of a building as long as the outer part is circular. Of course, the target pipes are gas, oil,
It is not limited to water pipelines, district heating and cooling pipes, etc., but also includes communication cables, etc.

Effects of the invention As is clear from the above explanation, the sealing device for buried pipes of the present invention penetrates through a sheath pipe or a hole in a structure, fits into a buried pipe that has a substantial double structure, A liquid fixing material that envelops the liquid and causes it to lose its fluidity is continuously arranged in a ring-shaped elastomeric tube that expands when press-fitted to fill the gap between the tubes and the sheath tube. The liquid that was press-fitted for expansion of the tube was adsorbed and fixed by the liquid fixing material, and the tube and the liquid were made into an integral elastic body, so the sheath tube and the main tube were completely insulated, and vibrations were prevented. It absorbs energy and protects the main pipe from earthquakes and vibrating objects on the ground, and it also blocks stray currents, increases corrosion protection, and secures the main pipe in the center of the sheath pipe.

In addition, even if the main pipe becomes eccentric with respect to the sheath pipe due to uneven settlement or vibration, the tube deforms elastically in the radial direction as appropriate, allowing this to be tolerated over a wide range without compromising airtightness. obtain.

Moreover, with this sealing device, the main pipe can be installed in the sheath pipe by simply fitting the tube into a predetermined position and then injecting a liquid such as water, thereby streamlining the construction work and reducing costs.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing an embodiment of a sealing device for buried pipes having a substantially double pipe structure according to the present invention, Fig. 2 is a front view of the same sealing device, and Fig. 3 is a conventional pipe end sealing device. FIG. 3 is a cross-sectional view of the sealing device. 1...tube, 2...liquid fixing material, 3...sheath tube, 4...main tube.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A pipe that penetrates through a sheath pipe or a hole in a structure to fit into a buried pipe that has a substantial double pipe structure, and expands when liquid is pressurized. A liquid fixing material that envelops the liquid and causes it to lose its fluidity is continuously placed in a ring-shaped elastomer tube that fills the gap between the sheath tube and the like, and the liquid that is press-fitted to expand the tube is A sealing device for pipes having a substantially double pipe structure, characterized in that the liquid fixing material is adsorbed and fixed. (2) Utility model registration claim 1, characterized in that the liquid fixing material is a hydrogel-forming substance.
A sealing device for buried pipes as described in Section. (3) The sealing device for buried pipes according to claim 1 or 2, wherein the liquid fixing material is a water-absorbing polymer.