JP2002372179A - Joint part structure of fire-resistant double-layer pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the joint part structure of fire-resistant double-layer pipes provided with an annular packing made of the inorganic heat insulating fiber and provided with a joint working structure having long-term safety, work simplicity and the improved fire-resistance when a fire breaks out. SOLUTION: In the joint part structure for connecting the fire-resistant double-layer pipe formed of an inner pipe and a fire-resistant and heat-insulating outer pipe for covering the inner pipe to a connector formed of an inner pipe and a fire-resistant and heat-insulating outer pipe, the inner pipe ends of the fire-resistant double-layer pipes to be connected to each other and inner pipe ends of the connector are fitted to each other, and the annular packing for covering the connected inner pipes and made of the thermal expansive fire- resistant material is interposed between opening edges of the outer pipes of the fire-resistant double-layer pipes and opening edges of the outer pipe of the connector opposite to each opening edge of the fire-resistant double-layer pipes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure of a fire-resistant double-layer pipe comprising an inner pipe and a fire-resistant outer pipe covering the inner pipe, and more particularly to an inner pipe and a fire-resistant pipe covering the inner pipe. Joint structure of a fire-resistant double-layer pipe connecting a fire-resistant double-layer pipe made of an outer pipe having heat resistance and heat insulation and a pipe joint consisting of an inner pipe and a fire-resistant and heat-insulated outer pipe covering the inner pipe It is about.

[0002]

2. Description of the Related Art Generally, a fire-resistant double-layered pipe in which an inner pipe made of a synthetic resin such as hard vinyl chloride is covered with a fire-resistant outer pipe, for example, a fiber-reinforced mortar coating pipe, has an inner pipe made of a synthetic resin. Since the inner peripheral surface is smooth, it has excellent chemical and water resistance, and it is covered with an outer tube and has excellent fire resistance and heat insulation, etc., so water supply pipes, drain pipes, ventilation pipes for ventilation, and power distribution for buildings Widely used for pipes.

[0003] FIG. 4 and FIG. 5 show such a joint structure for connecting a conventional fire-resistant double-layer pipe.

FIG. 4 is a cross-sectional view showing a connecting portion for connecting a pair of refractory double-layer pipes 21 with a pipe joint 24. In the figure, the fire-resistant double-layer pipes 21 and 21 are made of synthetic resin, for example, hard vinyl chloride, and are fire-resistant and heat-insulating properties such as fiber-reinforced mortar coating pipes that cover the inner pipes 22 and 22. Outer pipes 23, 23, and a pipe joint 24 is also made of an inner pipe 25 made of a synthetic resin such as hard vinyl chloride.
And an outer tube 26 having fire resistance or heat insulation such as fiber reinforced mortar for covering the inner tube 25. The inner diameter of the inner tube 25 of the pipe joint 24 is the same as that of the two-layer fire-resistant tubes 21, 21. Tubes 22, 2
2 has a size that allows the ends 22a, 22a to be fitted therein, and the refractory double-layer pipes 21, 21 fitted into the center of the inner peripheral surface thereof.
An annular projection 25b is provided for determining the fitting depth position by contacting the opening edges 22b, 22b.

In order to connect the refractory double-layer pipes 21, 21, the inner pipes 22 projecting outward from the open ends 23 b, 23 b of the outer pipes 23, 23 of the refractory double-layer pipes 21, 21 to be connected. 2
2 is coated with an adhesive in advance, and these ends 22a, 22a are respectively inserted and fitted from the opening edges 25a, 25a of the inner pipe 25 of the pipe joint 24, and the refractory two-layer pipe 2 is inserted.
The outer ends 23b, 23b of the outer tubes 23, 23 of the first and the second 21 are connected to the opening ends 26b, 26b of the outer tube 26 of the pipe joint 24 by being brought into contact with each other.

Next, the outer tube 2 of the refractory double-layer tubes 21
When cutting the outer pipes 23, 23 of the refractory double-layer pipes 21, 21 at the contact portions between the open end edges 23b, 23b of the pipe joints 24 and the open end edges 26b, 26b of the outer pipe 26 of the pipe joint 24. A slight gap due to the processing accuracy of
Since the outer tubes 23, 23 and the outer tube 26 are discontinuous,
A dry-curable joint material 27 mainly composed of water glass or cement is used to form open ends 23b, 23b of outer pipes 23, 23 of refractory double-layer pipes 21, 21 and open ends 26b of outer pipe 26 of pipe joint 24. , 26b is subjected to a joint treatment by a wet joint method.

As another joint treatment, a dry joint method shown in FIG. 5 is applied.

In this joint method, parts corresponding to those in FIG. 4 are given the same reference numerals in FIG. 5, and detailed description is omitted. Bent portion 31a corresponding to a step between the outer tube 26 and the outer peripheral surface of the outer tube 26
Bend into a substantially stepped cross section having a
1 and a band-shaped metal joint cover 31 having crimped surfaces 31b and 31c respectively in contact with the outer peripheral surface of the outer tube 23 and the outer peripheral surface of the outer tube 26 of the pipe joint 24.
3 and the outer tube 26 of the pipe joint 24 are wound around the outer tube 26, and the crimping surfaces 31b and 31c at both ends thereof are fastened with screws, nuts, or the like.

Further, another joint processing is disclosed in Japanese Patent No.
As shown in FIG. 5, an annular packing 33 made of an inorganic heat insulating fiber such as a ceramic fiber is attached to an opening edge 23b of an outer tube 23 of a fire-resistant double-layer tube 21 as shown in FIG. There is a dry joint method interposed between the pipe joint 24 and the open end 26b of the outer pipe 26 of the pipe joint 24 to be connected.

[0010]

However, in the joint treatment by the former wet joint method, the joint material applied to the contact portion between the refractory double-layer pipe and the pipe joint shrinks as it hardens with time, Cracks and peeling may occur, causing joint material to fall off.

In addition, the joint material is deteriorated by carbonation,
In some cases, it may be difficult to secure a stable joint processing function over a long period of time.

On the other hand, in the joint processing using the metal joint cover of the dry joint method, since the size and shape of the joint cover are set in advance, the shape is deformed due to an error in the dimensional accuracy in the production of the fire-resistant double-layer pipe. For example, when the cross-sectional shape is deformed from a circular shape to an elliptical shape, etc., it is difficult to mount it, and since it is made of metal, especially when used for a water supply pipe etc., sufficient heat insulating performance is obtained. Is not obtained, and the joint cover is corroded due to dew condensation, which may cause a problem that it is difficult to secure a stable joint processing function over a long period of time.

Further, since the two joint treatments are performed after the piping work on the building is completed, the work space is limited, the work is troublesome, it is difficult to obtain a uniform joint treatment function, and the construction period is long. It will also lead to

[0014] In the joint treatment in which an annular packing made of inorganic heat insulating fiber is interposed, the joint treatment is stable for a long period of time, and can be performed simultaneously with the piping work, thus simplifying the work. It has been shown to be effective enough for the joint treatment method for refractory double-layer pipes and pipe joints.

However, if the joint treatment is not sufficient and a gap is formed in the joint, a flame enters through the gap at the time of a fire, and the inner pipe made of synthetic resin melts and spreads, and the effect as a joint material is obtained. Can no longer be found,
Pipe joints may fall off.

Accordingly, an object of the present invention is to solve the problems in the prior art by providing long-term stability and simplicity of operation, as well as an annular packing made of inorganic heat-insulating fibers, as well as fire. In some cases, it is an object of the present invention to provide a joint structure of a fire-resistant double-layer pipe having a joint treatment structure having improved fire resistance.

[0017]

In order to achieve the above-mentioned object, a joint structure of a fire-resistant double-layer pipe according to the present invention comprises an inner pipe and a fire-resistant and heat-insulating outer pipe covering the inner pipe. In a joint structure of a fire-resistant double-layer pipe for connecting a fire-resistant double-layer pipe and a pipe joint consisting of an inner pipe and a fire-resistant and heat-insulating outer pipe for covering the inner pipe, The inner pipe end of the pipe is fitted and connected to the inner pipe end of the pipe joint, and the opening edge of the outer pipe of the fire-resistant double-layer pipe, and the opening edge of the outer pipe of the pipe joint facing the opening edge An annular packing made of a heat-expandable refractory material surrounding the joined inner tube is interposed between the first and second parts.

Further, the joint structure of the fire-resistant double-layered pipe according to the present invention may be provided at the opening edge of the annular packing and the outer pipe of the fire-resistant double-layered pipe and / or at the outer pipe edge of the annular packing and the fire-resistant double-layered pipe. The gap between the opening edges of the outer pipes of the opposed pipe joints is set to 10 mm or less.

Further, in the joint structure of the fire-resistant double-layer pipe according to the present invention, the inner pipe of each of the fire-resistant double-layer pipe and the pipe joint is a pipe made of a synthetic resin, and each outer pipe is a fiber-reinforced mortar-coated pipe. It is characterized by being.

Further, the joint structure of the fire-resistant double-layer pipe according to the present invention is characterized in that the annular packing is constituted by a plurality of packing members divided in an arc shape.

In the joint structure of the fire-resistant double-layer tube of the present invention, the annular packing is made of a material mainly composed of expandable graphite or water glass, or a flame-retardant elastomer containing an organic foaming agent. It is characterized by the following.

Other objects, features and advantages of the present invention will be apparent from the following detailed description of embodiments of the fire-resistant double-layer tube joint structure of the present invention with reference to the accompanying drawings.

[0023]

FIG. 1 is a cross-sectional view for illustrating and explaining one example of a joint structure of a refractory double-layer pipe according to the present invention.
FIG. 2 shows a joint for connecting a pair of fire-resistant double-layer pipes 1 and 1 to each other via a pipe joint 5, and FIG. 2 is a perspective view showing an annular packing 9 used in the joint structure of the fire-resistant double-layer pipe of FIG. It is.

As shown in FIG. 1, in the present invention,
The refractory double-layer pipes 1 and 1 are made of, for example, inner pipes 2 and 2 made of synthetic resin such as hard vinyl chloride, and a heat-insulating pipe that covers the inner pipes 2 and 2 and has fire resistance and heat insulation properties, for example, fiber-reinforced mortar coating. An inner tube 2 and an outer tube 4
A gap 3 is formed therebetween.

The pipe joint 5 for connecting the fire-resistant double-layer pipes 1 and 1 to each other also has an inner pipe 6 made of a synthetic resin such as hard vinyl chloride and the like, similarly to the fire-resistant double-layer pipes 1 and 1. And a fire-resistant and heat-insulating outer tube 8 such as a fiber-reinforced mortar-coated tube, and a gap 7 is formed between the inner tube 6 and the outer tube 8. The inner pipe 6 of such a pipe joint 5 has an inner diameter capable of fitting the ends 2a, 2a of the inner pipes 2, 2 of the refractory double-layer pipes 1, 1, and has an inner circumference of the inner pipe 6. At the center of the surface, there is provided an annular projection 6b for determining the position of the fitting depth of the inner pipes 2 and 2 of the refractory double-layer pipes 1 and 1 fitted into the inner pipe 6 of the pipe joint 5. The inner pipes 2 are fitted so that the edges 2b, 2b of the inner pipes 2, 2 abut on both sides of the annular projection 6b.

The refractory double-layer pipes 1 to be connected are
In order to connect with each other via the outer pipes 4, the ends 2a, 2a of the inner pipes 2, 2 projecting a predetermined length from the outer pipes 4, 4 of the refractory double-layer pipes 1, 1 Are mounted on the outer peripheral surfaces of the ends 2a, 2a of the inner tubes 2, 2, respectively, by attaching an annular packing 9 shown in a perspective view of FIG. These ends 2
a, 2a are both open edges 6a, 6a of the inner pipe 6 of the pipe joint 5.
And the inner ends 2b, 2b of the refractory double-layer pipes 1, 1 and the inner pipe 6 of the pipe joint 5 are integrated by firmly contacting the opening edges 2b, 2b with the annular projection 6b. And can be connected firmly.

With the annular packing 9 mounted, the annular packing 9 and the opening edge 4b of the outer tube 4 of the fire-resistant double-layer pipe 1 and / or the annular packing 9 and the opening edge 8b of the outer tube 8 of the pipe joint 5 When a gap is formed in the annular packing 9, the material of the annular packing 9 is a material mainly composed of expandable graphite which is a heat-expandable refractory material, a material mainly composed of water glass, or an organic foaming agent added to a flame-retardant elastomer. By adding the additive, the annular packing 9 thermally expands in the event of a fire to prevent the intrusion of flame from a gap, and the inner pipe can be prevented from melting and spreading, or the pipe joint can be prevented from falling off. .

The annular packing 9 and the open end 4b of the outer tube 4 of the refractory double-layer pipe 1 and / or the annular packing 9 and the pipe joint 5
The gap between the opening edges 8b of the outer tube 8 should be 10 mm or less, preferably 5 mm or less.

If the gap is wider than this, there is a risk that a flame may enter through the gap before the annular packing thermally expands and closes the gap in the event of a fire.

FIG. 3 is a cross-sectional view of a joint structure of a refractory double-layer pipe according to another embodiment of the present invention, and portions corresponding to those in FIG. 1 are denoted by the same reference numerals. In this embodiment, only the structure of the pipe joint is different from that of FIG. 1 described above, and the joint structure of the refractory double-layer pipe is substantially the same as described above.

That is, as shown in FIG. 3, the pipe joint 10 to which the refractory double-layer pipe 1 is joined is a so-called substantially T-shaped pipe joint and is made of a synthetic resin material such as hard vinyl chloride. An inner tube 11 and an outer tube 13 formed of a fire-resistant and heat-insulating fiber-reinforced mortar cladding tube or the like, which are overlapped so as to form a gap 12 between the inner tube 11 and cover the inner tube 11. ing. The inner pipe 11 and the outer pipe 13 have a substantially T-shape.
Has an inner end 11a having an inner diameter into which the end 2a of the inner pipe 2 of the refractory double-layer pipe 1 is fitted.
A step 11b for determining the fitting depth of the inner tube 2 by contacting the opening edge 2b of the inner tube 2 is formed. In addition, the outer tube 13
Has substantially the same shape as the inner tube 11.
And is provided so as to cover through a gap 12.

As described above, the annular packing 9 is connected to the end 2a of the inner pipe 2 projecting from the outer pipe 4 of the fire-resistant double-layer pipe 1 by a predetermined length in the same manner as described above. The end 2a of the pipe joint 10 is attached and the outer peripheral surface thereof is coated with an adhesive.
1, the inner pipe 2 and the inner pipe 11 are integrated, and the annular packing 9 is provided with the outer pipe 4 of the fire-resistant double-layer pipe 1 and the outer pipe 13 of the pipe joint 10 respectively. Opening edge 4 of
By interposing in a compressed state between b and 13b, the refractory double-layer pipe 1 and the pipe joint 10 can be integrally connected.

The effect of the annular packing 9 is the same as that described with reference to FIG. 1. Even if there is a gap between the annular packing 9 and the opening edge 4b and / or the opening edge 13b, it is possible to use a heat-expandable refractory material in a fire. The annular packing 9 thus formed thermally expands and closes the gap to prevent the flame from entering.

(Example) A pipe having a joint structure in which a pair of refractory double-layer pipes 1 and 1 shown in FIG. 1 were connected to each other via a pipe joint 5 was subjected to a fire resistance test.

In the fire resistance test, a heating test was carried out with the lower burner B in the pipe shown in FIG.

As shown in the figure, the inside of the heating chamber C is surrounded by a concrete wall, and the flame does not leak from the inside to the outside of the heating chamber C. The piping is heating room 1
A fire-resistant double-layer pipe 1 is suspended and supported by a suitable support band or the like on the upper part of the pipe, and the fire-resistant double-layer pipe 1 is connected by a pipe joint 5. However, the refractory double-layer pipe 1 of the pipe penetrates the wall at two places and extends outside the heating chamber C,
The end of the refractory double-layer pipe 1 extending outside the heating chamber C is open, and the burner B disposed at the lower part of the heating chamber C
When the pipe is broken due to the heating, the pipe joint 5 is dropped or the like by heating, the flame leaks from the broken through portion of the pipe.

Heating method: As a heating method in the test,
JIS A 1304 “Fire resistance test method for building structural parts”
The heating was performed so as to follow the standard heating curve specified in the above.

Heating time: Heating was performed for a maximum of 4 hours in the test.

Observation: The structure of the joint of the refractory double-layer pipe during heating and the state of leakage of the flame from the wall penetration of the refractory double-layer pipe were observed.

Test frequency: The test was performed three times.

As a comparison with the present invention, an annular packing made of inorganic fibers is used instead of the annular packing made of a heat-expandable refractory material in the joint structure of the fire-resistant double-layer pipe of the present invention shown in FIG. Was compared. The annular packing used for the test was as follows: (1) Annular packing made of a heat-expandable refractory material: "Cut Sheet G" (trade name) manufactured by A & A Material Co., Ltd .: outer diameter 144 mm, inner diameter 112 mm, thickness 10 mm ( 2) Annular packing made of inorganic fiber: "One Touch Media" (trade name) manufactured by A & A Material Co., Ltd .: outer diameter 144 mm, inner diameter 112 mm, thickness 10 mm

[0042]

[Table 1]

According to the joint structure of the fire-resistant double-layer pipe using the annular packing made of the heat-expandable refractory material of the present invention, the annular packing expands to protect the joint, and the pipe of the fire-resistant double-layer pipe falls off. There was no leakage of the flame from the heating chamber to the outside.

The pipe of the fireproof double-layer pipe using the annular packing made of the inorganic material to be compared had a test piece in which the fitting was dropped, and the flame leaked out of the heating chamber.

Further, according to the above-described test method, the annular packing made of the heat-expandable refractory material having the same shape as that described above was used, and the annular packing and the opening edge of the outer pipe of the fire-resistant double-layer pipe, and the annular packing and the pipe joint The test was carried out using a test piece constructed with a 10 mm gap between it and the opening edge.

As a result, the annular packing expanded and the joint was protected, the fireproof double-layered pipe did not fall off in all three specimens, and there was no leakage of the flame from the heating chamber to the outside. According to the above-described embodiment, even with the annular packing having fire resistance, the fire enters the joint of the pipe of the fire-resistant double-layer pipe due to the fire, causing the inner pipe to melt and spread the fire, and the concrete wall is damaged. However, it was seen that the fire spread to the next room.

[0047]

As described above, the joint structure of the fire-resistant double-layer tube according to the first aspect of the present invention comprises an inner tube and an outer tube having a fire-resistant and heat-insulating property covering the inner tube. In a joint structure of a fire-resistant double-layer pipe for connecting a fire-resistant double-layer pipe and a pipe joint consisting of an inner pipe and a fire-resistant and heat-insulating outer pipe covering the inner pipe, a fire-resistant double-layer pipe to be connected to each other Of the outer pipe of the fire-resistant double-layer pipe, and the opening edge of the outer pipe of the pipe joint facing the opening edge. An annular packing made of a heat-expandable refractory material surrounding the joined inner pipe is interposed between the inner pipe and the outer end of each outer pipe of the refractory double-layer pipe and the pipe joint. Joint treatment is performed by interposing an annular packing made of a heat-expandable refractory material between Ground processing work is performed, excellent in its workability, it is possible to simplify and shorten the construction period of the work,
In addition, a joint structure of a fire-resistant double-layer pipe excellent in fire resistance can be obtained.

According to a second aspect of the present invention, there is provided a joint structure for a refractory double-layer pipe, wherein an annular packing is mounted and an opening edge of an outer pipe of the refractory double-layer pipe and / or the annular packing is connected to the annular packing. Even when a gap is formed at the opening edge of the outer pipe of the pipe joint facing the outer pipe edge of the fire-resistant double-layer pipe, if the gap is 10 mm or less, the pipe is made of a heat-expandable refractory material. The annular packing expands in the event of a fire, closes the gap, prevents the intrusion of flame from the gap, and prevents the inner pipe from melting and spreading, and the pipe joint from falling off.

According to a third aspect of the present invention, there is provided a joint structure of a fire-resistant double-layer pipe, wherein each of the inner pipes of the fire-resistant double-layer pipe and the pipe joint is a pipe made of synthetic resin, and each of the outer pipes is fiber-reinforced. Since it is a mortar cladding tube, the fiber-reinforced mortar cladding tube having excellent fire resistance has an effect of preventing fire from spreading to an adjacent room due to falling off of the pipe of the fire-resistant double-layer tube at the time of fire.

In the joint structure for a fire-resistant double-layer pipe according to a fourth aspect of the present invention, the annular packing is constituted by a plurality of packing members divided in an arc shape. It is not necessary to fit an annular packing into the inner pipe of the fire-resistant double-layer pipe, and it can be used by pushing it into the gap, and can also be used as a joint material for repair of a part already piped.

According to a fifth aspect of the present invention, in the joint structure for a fire-resistant double-layer pipe, the annular packing is made of a material mainly composed of expandable graphite or water glass, or a flame-retardant elastomer to which an organic foaming agent is added. This is a structure using a packing that utilizes properties of fire resistance and thermal expansion obtained from a material selected from any of the above.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a joint structure of a fire-resistant double-layer pipe of the present invention.

FIG. 2 is a perspective view of an annular packing used in the joint structure of the refractory two-layer pipe of the present invention shown in FIG. 1;

FIG. 3 is a cross-sectional view showing another embodiment of the joint structure of the refractory two-layer pipe of the present invention.

FIG. 4 is a cross-sectional view showing an example of a conventional joint structure of a fire-resistant double-layer pipe.

FIG. 5 is a cross-sectional view showing another example of a conventional joint structure of a fire-resistant double-layer pipe.

FIG. 6 is a construction drawing of a fire resistance test.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refractory double-layer pipe 2 Inner pipe 2a end 4 Outer pipe 4a end 4b Opening edge 5 Pipe joint 6 Inner pipe 6a end 8 Outer pipe 8a end 8b Opening edge 9 Annular packing 10 Pipe joint 11 Inner wall 11a end Part 11b Step 12 Gap 13 Outer tube 13a End 13b Opening edge

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2D060 AC01 2D061 AB10 AC02 3H015 BA01 BA05 BB05 BC01 BC07 BC08

Claims (5)

[Claims] 1. A fire-resistant double-layer pipe comprising an inner pipe and a fire-resistant and heat-insulating outer pipe covering the inner pipe, and a fire-resistant and heat-insulating outer pipe covering the inner pipe and the inner pipe. The joint structure of a fire-resistant double-layer pipe for connecting a pipe joint with a pipe joint, the inner pipe end of the fire-resistant double-layer pipe to be connected with the inner pipe end of the pipe joint is fitted and connected, and the fire-resistant double-layer pipe is connected. An annular packing made of a heat-expandable refractory material surrounding the joined inner pipe is interposed between the opening edge of the outer pipe of the above and the opening edge of the outer pipe of the pipe joint facing the opening edge. The joint structure of a fire-resistant double-layer pipe characterized by the following. 2. A gap between an opening edge of the outer ring of the annular packing and the outer pipe of the fire-resistant double-layer pipe and / or a gap between an opening edge of the outer pipe of the pipe joint opposed to the outer pipe edge of the annular packing and the outer pipe of the fire-resistant double-layer pipe. 2. The joint structure for a fire-resistant double-layer pipe according to claim 1, wherein 3. The pipe according to claim 1, wherein each inner pipe of the refractory double-layer pipe and the pipe joint is a pipe made of a synthetic resin, and each outer pipe is a fiber-reinforced mortar clad pipe. Fire-resistant double-layer pipe joint structure. 4. The joint structure for a fire-resistant double-layer pipe according to claim 1, wherein the annular packing is constituted by a plurality of packing members divided in an arc shape. 5. The method according to claim 1, wherein the annular packing is made of a material mainly composed of expandable graphite or water glass, or a flame-retardant elastomer to which an organic foaming agent is added. The joint structure of the refractory double-layer pipe according to any one of the above.