JP2001108158A - Double-piping structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double piping structure of a pipe for oil (gasoline), gas or the like, which is capable of preventing oil leakage by lining a pipe with FRP (fiber reinforced composite material) and detecting the occurrence of oil leakage by disposing a detecting sensor. SOLUTION: The peripheral surface of a steel pipe 16 is lined with the FRP (fiber reinforced composite material) 17, and a lead wire is interposed between the steel pipe 16 and the FRP (fiber reinforced composite material). The lead wire is interposed along the lower surface of the steel pipe 16 to form a designated gap between the steel pipe 16 and the FRP (fiber reinforced composite material) 17, whereby when oil leakage from the steel pipe 16 occurs, leak oil is guided to the downstream part of the steel pipe 16 and oil leakage is detected by the detecting sensor 11. The output of the detecting sensor 11 is fed to an oil leakage detecting monitor 14 to inform a worker of the occurrence of oil leakage and the position of the oil leakage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to oil (gasoline),
The present invention relates to piping for gas and the like, and more particularly to a double piping structure having double piping.

[0002]

2. Description of the Related Art At present, soil pollution due to oil (gasoline) leakage and disasters due to gas leakage have become major social problems. Such oil leaks and gas leaks often occur due to old pipes and corrosion of the pipes due to long-term use.

[0003] For this reason, in a conventional facility for handling dangerous substances such as a fueling station or an underground tank storage, steel pipes (steel pipes) are used, and painted or coated to prevent corrosion of the outer surface. Has been treated.

[0004]

However, even if the above-mentioned conventional treatment is performed, the pipes are corroded due to long-term use, and especially pipes buried underground, coastal pipes affected by salt damage, or long pipes. This is an important issue in distance piping. For example, underground pipes cause soil contamination as described above, and coastal pipes (ground pipes) cause fires and explosions. Furthermore, it is difficult to identify a leak point in a long-distance pipe.

[0005] In order to solve the above problems, the present invention is to cover the piping with FRP (fiber reinforced composite material) to prevent oil leakage and the like, and to provide a detection sensor to prevent the occurrence of oil leakage and the like.
An object of the present invention is to provide a double piping structure capable of detecting an occurrence location.

[0006]

According to a first aspect of the present invention, there is provided a pipe and a fiber which is provided on an outer periphery of the pipe to prevent a leakage material from the pipe from leaking outside. This can be achieved by providing a double piping structure comprising a reinforced composite.

The pipes used in this embodiment are, for example, underground pipes for supplying oil (gasoline) to a buried tank installed in a gas station, gas supply pipes, and long-distance pipes. Become.

[0008] The pipe may be made of any of various materials such as a steel pipe, a stainless steel pipe, a galvanized steel pipe, and the like. The outer circumference of these pipes is covered with FRP (fiber reinforced composite material).

[0009] With this configuration, pipes such as steel pipes and stainless steel pipes are corroded by long-term use.
Even if oil (gasoline) or gas leaks occur, F
RP (fiber reinforced composite material) does not leak into the ground or the ground.

[0010] According to an aspect of the present invention, the above object is provided.
A pipe, a fiber-reinforced composite material that is provided on the outer periphery of the pipe and that prevents leakage material from the pipe from being discharged to the outside;
Provided is a double piping structure comprising: a lead wire of the leaking material provided between the pipe and the fiber-reinforced composite material; and a sensor for detecting the leaking material provided between the pipe and the fiber-reinforced composite material. Can be achieved by doing

This embodiment is based on the first aspect of the present invention.
Further, even when oil leakage or gas leakage occurs, a leakage material such as oil (gasoline) or gas is guided to a detection sensor by a conducting wire (lead wire), and leakage is detected by the detection sensor.

With this configuration, it is possible to not only prevent oil (gasoline) leakage or gas leakage itself,
Leakage can be detected. For example, the output of a detection sensor can be monitored by an oil leak detection monitor to notify an operator of an oil (gasoline) leak or a gas leak.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the leaking material is, for example, oil, and a fourth aspect of the present invention is the first or the second aspect of the present invention. The leaking material is, for example, a gas, and is configured to specify the leaking material.

According to a fifth aspect of the present invention, in the second aspect of the invention, the conductive wire is disposed, for example, along a lower surface of the pipe. That is, the conductive wire is a wire that guides the leak material to the detection sensor, and by arranging along the lower surface of the pipe, the leak material that reaches the lower surface of the pipe along the circumferential surface of the pipe is formed by the conductive wire. And flows along the lower surface of the pipe to the detection sensor disposed at the most downstream position.

Therefore, with this configuration, oil leaks and the like can be reliably detected by the detection sensor, and, for example, the worker can reliably know the oil leaks and the like by the detection monitor.

According to a sixth aspect of the present invention, in the second aspect of the invention, the conductive wire is disposed, for example, along upper and lower surfaces of the pipe. In the case of this example, by arranging a conductive wire also on the upper surface of the pipe, a passage for a leaked material due to oil leakage or the like is further secured, and the detection accuracy of the leaked material is improved.

According to a seventh aspect of the present invention, in the second aspect of the present invention, the conductive wire is arranged in a mesh shape on a peripheral surface of the pipe, for example. With such a configuration, the passage of the leaking material is also secured on the peripheral surface of the pipe, and the leaking material leaked from the pipe is more reliably guided to the lower surface of the pipe,
Leakage from the peripheral surface of the pipe can also be reliably detected.

According to an eighth aspect of the present invention, in the second aspect of the invention, the conductive wire is spirally disposed on a peripheral surface of the pipe. Even with such a configuration, the passage of the leaking material is secured on the peripheral surface of the pipe, and the leaking material leaking from the pipe can be reliably guided to the lower surface of the pipe, and the leak can be reliably detected.

According to a ninth aspect of the present invention, in the second aspect, the detection sensor is disposed, for example, on a lower surface of a downstream portion of the pipe. That is, by arranging the detection sensor on the lower surface of the downstream portion of the pipe as described above, the leak sensor guided by the conductive wire can be reliably detected by the detection sensor.

According to a tenth aspect of the present invention, in the second aspect of the invention, a plurality of the detection sensors are provided, for example, on a lower surface of the pipe. With this configuration, it is possible to know at which position in the pipe oil leakage or the like has occurred. For example, by displaying this position on an oil leakage detection monitor, a more reliable leak detection system can be provided. .

According to an eleventh aspect, in the invention according to the second aspect, a plurality of the detection sensors are provided on a peripheral surface of the pipe. With this configuration, it is possible to immediately detect a leak generated on the peripheral surface of the pipe, and to easily specify the position.

With this configuration, the repair position of the pipe can be accurately determined, and the repair work can be easily performed.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system configuration diagram illustrating a double piping structure of the present embodiment. Note that the system diagram shown in the figure applies the double piping structure of the present embodiment to piping for storing oil (gasoline) in an underground tank. In this example, a tank buried under the gas station will be described as an underground tank.

Referring to FIG. 1, an underground tank 1 has an oil supply pipe 2 for filling oil (gasoline), an oil supply pipe 3 for sucking oil (gasoline) from the underground tank 1, a ventilation pipe 4 for ventilating the underground tank 1, and an underground tank. Oil (gasoline) stored in tank 1
Is provided with a liquid level gauge 5 for measuring the liquid level of the liquid. Also,
The underground tank 1 is buried at a predetermined depth from the ground surface, and concrete (not shown) is provided on the underground tank 1.

The lubrication pipe 2 is provided with a lubrication port 6 on the surface of the ground, through which lubrication of oil (gasoline) is performed. In addition, the oil supply pipe 3 is provided with instruments 7 such as a measuring instrument and a pump on the surface of the ground, and sucks oil (gasoline) from the underground tank 1.
Measure the oil (gasoline) to be sucked. In addition, lubrication pipe 2
Is provided with a valve 8, and the oil supply pipe 3 is provided with a valve 9. When the underground tank 1 is repaired / repaired, the valves 8 and 9 are closed. The ventilation pipe 4 has a ventilation opening 10.
Is provided to discharge gas generated in the underground tank 1.

On the other hand, a detection sensor 11 for detecting oil (gasoline) leakage is provided at a predetermined location of the oil supply pipe 2, and a detection sensor 12 for detecting oil (gasoline) leakage at a predetermined location of the oil supply pipe 3. Is provided. These detection sensors 11 and 12 are connected to an oil leak detection monitor 14 by an electric transmission cable 13, and are connected to an oil supply pipe 2 and an oil supply pipe 3.
This is a configuration for detecting the oil leak of the above.

FIG. 2 is a view for explaining the cross-sectional structure of the above system configuration. The cross-sectional view shown in FIG. 2 particularly shows a cross-sectional structure including the above-described lubrication pipe 2 and the transmission cable 13.

As described above, the lubrication pipe 2 is provided with the lubrication port 6, oil (gasoline) is lubricated from the lubrication port 6, and the oil (gasoline) is stored in the underground tank 1 through the lubrication pipe 2. . As shown in the figure, the lubricating pipe 2 has a double structure, and a steel pipe 16 is used as a base pipe and FRP (fiber reinforced composite material) is used.
17 is covered. Here, the structure of the lubrication pipe 2 having the above configuration will be described in detail.

FIG. 3A is a sectional view of the lubricating pipe 2, and FIG. 3B is an enlarged view of a dotted circle A in FIG. 3A. As described above, the lubrication pipe 2 has a double structure, and the steel pipe 16 is covered with the FRP (fiber reinforced composite material) 17. Further, as shown in FIG. 1B, a lead wire (conductive wire) 18 is interposed between the steel pipe 16 and the FRP (fiber reinforced composite material) 17. This lead wire (conductor)
18 is a steel pipe 16 and FRP (fiber reinforced composite material) 1
7, a wire for forming a predetermined gap between
It is disposed linearly along the lower surface 16b of the steel pipe 16.

FIG. 4 is a cross-sectional view of the lubricating pipe 2, and is a cross-sectional view taken along the line BB of FIG. 3 (a). Lubrication pipe 2
As shown in FIG. 3 (b), the lower part has a configuration in which a lead wire (conductive wire) 18 is interposed between a steel pipe 16 and an FRP (fiber reinforced composite material) 17. On the other hand, the upper part of the lubrication pipe 2 has a structure in which FRP (fiber reinforced composite material) 17 is stuck twice. That is, the steel pipe 16 has the first FR
P (fiber reinforced composite material) 17a is provided, and FRP
FRP (fiber reinforced composite material) 17b is adhered on (fiber reinforced composite material) 17a. A primer 19 is applied between FRPs (fiber reinforced composite materials) 17a and 17b.

The FRP (fiber reinforced composite material) 17 used in this example is based on an epoxy acrylate resin,
It is a thin sheet reinforced with glass fiber, and the upper and lower surfaces are covered with a transparent plastic film. The coating with the primer 19 is performed by FRP (fiber reinforced composite material).
Correcting the unevenness of the member for bonding 17 to enhance the adhesiveness, and when air bubbles occur between FRP (fiber reinforced composite material) 17 and primer 19 after coating and drying, FRP (fiber reinforced composite material) This is for facilitating peeling, reattachment, and defoaming. In addition, primer 1
Reference numeral 9 denotes an epoxy acrylate resin that is cured by mixing an accelerator and a curing agent.

The FRP (fiber reinforced composite material) 17a covering the peripheral surface of the steel pipe 16 is a state in which the plastic film formed on the surface of the FRP (fiber reinforced composite material) 17a is left as it is. Steel piping 16
A lower layer FRP (fiber reinforced composite material) 17a is wound around, and then an upper layer FRP (fiber reinforced composite material) 17b is wrapped for a predetermined distance, and the upper layer is adhered to the lower layer FRP (fiber reinforced composite material) 17a. With this configuration, the steel pipe 16 and the lower layer FRP (fiber reinforced composite material) 17
A gap is formed between the points a, and serves as a path for leaked oil described later.

Next, the process of installing the above-described lubricating pipe 2 having a double pipe structure will be described below. First, the outer surface of the pipe (steel pipe 16) used for many years is cleaned. After this cleaning, a pressure test of the steel pipe 16 is performed, and dust and dirt on the outer surface of the steel pipe 16 are wiped off with a waste cloth.

Next, an operation of attaching the lead wire (conductive wire) 18 is performed. The arrangement of the lead wire (conductive wire) 18 allows the leakage oil to be guided to the detection sensor 11 even if leakage oil is generated in the future.
It is installed along the pipeline. In addition, a lead wire (conductive wire) 18
Are linearly arranged along the lower surface of the steel pipe 16 and are fixed at regular intervals so that the lead wires (conductors) 18 do not loosen. This fixing is performed using the same material as the lead wire (conductive wire) 18. That is, it is fixed with an insulating material.

Next, the detection sensor 11 is mounted.
The detection sensor 11 is connected to the steel pipe 16 as described above.
Is installed at the most downstream part of the system to detect oil leakage. In addition, the detection sensor 11 is fixed in the same manner as the above-described lead wire (conductive wire) 18, and an insulating material is wound around the detection sensor 11 to reliably insulate the steel pipe 16 from the detection sensor 11.

FIG. 5 is a cross-sectional view for explaining the structure of the most downstream portion of the steel pipe 16. As shown in the figure, the detection sensor 11 is provided at the tip of a lead wire (conductor) 18 and is insulated by insulating materials 22a and 22b. Further, the detection sensor 11 is connected to the oil leak detection monitor 14 by the above-described transmission cable 13. The transmission cable 13 is protected by the conduit 23.

Next, an FRP (fiber reinforced composite material) 17 is provided. The arrangement of this FRP (fiber reinforced composite material) 17
After attaching the lead wire (conductor) 18 and the detection sensor 11 to the steel pipe 16, an FRP (fiber reinforced composite material) 17 is wound around the steel pipe 16. At this time, as described above, the plastic film on the surface of the FRP (fiber reinforced composite material) 17 is not peeled off, the FRP (fiber reinforced composite material) 17 (17a) is wound around the peripheral surface of the steel pipe 16, and the FRP is placed above the pipe. (Fiber reinforced composite material) 17 (17b), the plastic film is peeled off only at the overlapped portion, and after primer coating, FRP (fiber reinforced composite material)
b) is attached. By this processing, the overlapping portions of the FRPs (fiber reinforced composite materials) 17a and 17b shown in FIGS. 4 and 5 are formed.

In this case, the thickness of the FRP (fiber reinforced composite material) 17 in the overlapped portion is (added value of 17a and 17b), for example, 5 cm or more. Therefore, the steel pipe 16
And a FRP (fiber reinforced composite material) 17 having a double pipe structure, and a lead wire (conductor) 18 is disposed between the steel pipe 16 and the FRP (fiber reinforced composite material) 17.
A predetermined gap (micro space) is formed.

At the most downstream part of the steel pipe 16,
In order to prevent oil (gasoline) from leaking from the gap (micro space), as shown in FIG. 5, a primer coating 25 is applied to the end surface of the FRP (fiber reinforced composite material) 17 (17a, 17b). Further, a primer coating 26 is also performed on the steel pipe 16, and an FRP (fiber-reinforced composite material) 17 (17 c) is covered on the primer coatings 25 and 26.

Next, an airtight test of the gap (small space) is performed. This test is performed by inserting an injection needle for an airtight test into an FRP (fiber reinforced composite material) 17 and injecting test oil (gasoline) into the gap. After the airtight test, the pierced injection needle was withdrawn, and FRP was
(Fiber reinforced composite material) 17 is laminated and pasted. Thereafter, ultraviolet rays are irradiated to cure the FRP (fiber reinforced composite material) 17.

Next, electrical wiring work is performed. This construction
This is a process of wiring the transmission cable 13 connected to the oil leakage detection sensor 11 attached to the oil leakage detection monitor 14, and extending the transmission cable 13 to the oil leakage detection monitor 14. 14 is attached. The oil leak detection monitor 14 has an LED display unit.
The detection results of the twelve detection sensors 11 can be displayed by these LEDs.

In the above description, the lubrication pipe 2 has been particularly described. However, the lubrication pipe 3 has the same configuration, and the steel pipe 16 has an FRP (fiber reinforced composite material) 17.
Is covered. Also, steel pipe 16 and FR
Lead wires (conductors) 18 between P (fiber reinforced composite materials) 17
Is interposed.

The operation of preventing oil (gasoline) leakage and detecting oil leakage in the configuration of the oil supply pipe 2 and the oil supply pipe 3 provided in the underground tank 1 having the above-described configuration will be described below. If the oil supply pipe 2 or the oil supply pipe 3 is deteriorated due to long-term use, a crack is generated in the pipe, and oil leaks from the location. If a crack is formed on the peripheral surface of the pipe (for example, the lubrication pipe 2), the oil leaks from the location. However, according to the double piping structure of this example, the peripheral surface of the piping (for example, the lubrication pipe 2) is FRP
(Fiber reinforced composite material) 17
The leaked oil (gasoline) does not leak to the outside. Therefore, soil pollution due to oil (gasoline) leakage can be reliably prevented.

The oil leaking from the pipe (for example, the lubrication pipe 2) is supplied to the steel pipe 16 and the FRP (fiber reinforced composite material) 1.
It flows to the lower surface of the steel pipe 16 through the gap formed between the pipes 7. In this case, the leaked oil (gasoline) flows through a gap formed between the plastic film surface of the steel pipe 16 and the FRP (fiber reinforced composite material) 17.

As described above, the leaked oil that has reached the lower surface of the steel pipe 16 flows downstream through the gap formed by the above-described lead (conductive wire) 18, and
6 reaches the position of the detection sensor 11 disposed at the most downstream position. Then, oil leakage is detected by the detection sensor 11.

FIGS. 6A and 6B show the detection sensor 11.
FIGS. 7A and 7B are diagrams for explaining the detecting operation of FIG. 7, wherein FIG. 7A shows a state in which no leaking oil is detected, and FIG. 7B shows a state in which leaking oil is detected. In addition, (a) and (b) in the same drawings indicate an insulating material in the detection sensor 11 and indicate a swellable resin.
● indicates a conductive material and indicates carbon particles.

For example, when there is no oil leakage, the current supplied from the oil leakage detection monitor 14 flows through →→→→→ and is sent to the oil leakage detection monitor 14 as shown in FIG. Can be At this time, the detection sensor 11
Is a preset value, and the oil leak detection monitor 14 does not turn on the LED, for example.

On the other hand, when oil leakage occurs as described above,
The leaked oil reaches the detection sensor 11 via the above path, and swells the swellable resin ○. For this reason, the state inside the detection sensor 11 is as shown in FIG. 3B, and the distance between the carbon particles ● is increased by the swollen swellable resin (large 印 mark), and the electric resistance increases. The oil leak detection monitor 14 detects this and knows the oil leak. In this case, the oil leak detection monitor 14 turns on the LED (or blinks the LED) to notify of the oil leak. At this time, a buzzer may be sounded at the same time.

By performing the processing as described above, the oil leak can be reliably detected, and the position of the oil leak can be specified. That is, by adopting the double piping structure of this example, not only can it be possible to prevent oil leakage, but also by using an oil leakage detection system,
It is a very effective means for safety management because oil leaks can be found quickly.

In the above embodiment, the double piping structure of the present invention is applied to oil leakage. However, the present invention is not limited to oil leakage but can be applied to gas leakage countermeasures.
Is a gas sensor, and the oil leak detection monitor 14 is also configured to display the occurrence and location of gas leakage. Further, the gas may be a gas generated from oil (gasoline) itself or a gas flowing through a pipe.

In this embodiment, the steel pipe 16 has been described. However, the present invention is not limited to the steel pipe, but may be any stainless steel pipe, carbon steel pipe, polyethylene coated steel pipe, nickel chrome alloy pipe, aluminum alloy pipe, lead pipe, galvanized steel pipe, or the like. It can be applied to various pipes.

In the above description of the embodiment, the lead wire (conductor) 18 is provided along the lower surface of the steel pipe 16, but may be provided as shown in FIG. Further, the detection sensor 11 may be provided as shown in FIG. For example, FIG. 1A shows a configuration in which lead wires (conductors) 18 are arranged in a mesh shape on the peripheral surface of a steel pipe 16, and oil leakage or the like is quickly caused by a gap formed by the lead wires (conductors) 18. Can be detected. Further, by arranging the detection sensors 11 in a mesh form as shown in FIG.

FIG. 5B shows a configuration in which a lead wire (conductor) 18 is spirally disposed on the peripheral surface of the steel pipe 16. In this case, the lead wire (conductor) 18 is formed by the lead wire (conductor) 18. Oil leaks and the like can be quickly detected by the gap, and the oil leaks and the like can be detected even earlier by arranging the detection sensors 11 in a mesh as shown in FIG.

FIG. 3C shows a configuration in which lead wires (conductors) 18 are provided on the upper and lower surfaces of the steel pipe 16. In this case, the lead wires (conductors) 18 can be saved. By arranging the detection sensor 11 in the same manner as shown in g), it is possible to provide a cost-effective detection system for oil leakage and the like. The configuration shown in FIG. 3D is the above-described wiring example, and the configuration shown in FIG.
This is an example in which they are arranged along 18.

Although the oil leak detection monitor 14 used in the above two embodiments detects a change in resistance, the change in resistance is converted into a change in voltage by the circuit shown in FIG. It may be configured to detect. That is, the twelve comparators 20a to 20l and the OR (O
R) A gate 21 is provided, and outputs of, for example, twelve detection sensors are supplied to inverting inputs (-inputs) of the corresponding comparators 20a to 20l. Further, the comparators 20a to 20a
The reference voltage (Vref) is applied to the non-inverting input (+ input) of 20 l.
And the comparators 20a to 20l output a low signal to the OR gate 21 while a voltage higher than the reference voltage (Vref) is supplied from the detection sensor 11, but the output of the detection sensor 11 is higher than the reference voltage (Vref). When it becomes smaller, a high signal is output to the OR gate 21. Note that a normal predetermined voltage V is supplied to the inverting inputs (−inputs) of the comparators 20a to 20l via the resistor R.

With this configuration, for example, the resistance value of the detection sensor 11 that has detected an oil leak increases, and the inverted inputs (−inputs) of the corresponding comparators 20a to 20l.
Are supplied with the resistors R and R1 and the divided voltage of the resistance value of the detection sensor 11, and when the voltage becomes lower than the reference voltage (Vref), the comparators 20a to 2 correspond to the high signals.
0l is output. Therefore, the oil leak detection monitor 14
In response to this signal, the LED is turned on or blinks to notify an oil leak or the like.

In FIG. 8, the OR gate 21
If the configuration is such that the LEDs are directly lit or blinked by the outputs of the respective comparators 20a to 20l without passing through, the corresponding 12 LEDs can be lit or blinked.

The overlapping structure of the FRP (fiber reinforced composite material) 17 may be different from that described above. That is, although FIG. 9A shows the superimposed structure described above, the structure shown in FIG. 9B or FIG. 9C may be used. For example, in the case of FIG. 1B, FRP (fiber reinforced composite material) 1
7 (17a) at the upper part,
5 and its vicinity are coated with a primer 19, and an FRP (fiber reinforced composite material)
(17b) is attached. In this case, FRP
(Fiber reinforced composite material) The overlap length of 17a and 17b is
For example, it is about 5 cm.

In the case of FIG. 9C, when disposing the FRP (fiber reinforced composite material) 17a, the non-deployed portion 16 '(for example, about 3/4) is left on the steel pipe 16,
When disposing the (fiber-reinforced composite material) 17b, the non-arranged portion 16 'is covered and the FRP (fiber-reinforced composite material)
Overlay b. In this case, primer coating 1
9 and the overlap length of two FRPs (fiber reinforced composite materials) 17a and 17b is set to about 5 cm. Further, in this case, the FRP (fiber reinforced composite material) 17a is formed in advance in, for example, a construction site or the like, and the FRP formed during the construction is formed.
A process of fitting RP (fiber reinforced composite material) 17a to the steel pipe 16 is performed.

In the above-described embodiment, an example of an underground tank such as a gas station has been described. However, other underground tanks, refueling offices, oil (gasoline) and gas transfer offices, and the like may be used. Applicable for underground piping.

This embodiment is not limited to underground pipes, but can be applied to exposed pipes in coastal areas where corrosion is likely to occur or long-distance pipes. Further, in the above description, the disposition of the FRP (fiber reinforced composite material) 17 on the steel pipe 16 is as follows.
Although the plastic film is not peeled off, the plastic film may be peeled off and directly attached to the steel pipe 16.

The pipe from which the plastic film is peeled as described above is particularly called a double shell pipe, and the pipe to which the plastic film is directly adhered without being peeled may be defined as a double pipe.

[0063]

As described above, according to the present invention,
Even if oil leakage or the like occurs due to corrosion or the like caused by aging, oil leakage or the like to the outside can be prevented by the FRP (fiber reinforced composite material) covered on the pipe.

Further, by using the detection sensor, it is possible to detect an oil leak, and it is also possible to specify a location such as an oil leak.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a double piping structure of the present invention.

FIG. 2 is a diagram illustrating a cross-sectional structure of FIG.

3A is a cross-sectional view of the lubrication pipe, and FIG. 3B is an enlarged view of a dotted circle A in FIG. 3A.

FIG. 4 is a sectional view taken along line BB of the lubrication pipe shown in FIG. 3 (a).

FIG. 5 is a cross-sectional view illustrating the structure of the most downstream portion of the steel pipe.

FIG. 6A is a diagram illustrating a state where no leaking oil is detected, and FIG. 6B is a diagram illustrating a state where a leaking oil is detected.

7 (a) shows the arrangement of stitch-shaped lead wires (conductors), FIG. 7 (b) shows the arrangement of spiral lead wires (conductors), and FIG. (D) shows a configuration in which a lead wire (conductor) is provided on the lower surface, (e) shows an arrangement of a stitch-shaped detection sensor, and (f) shows a spiral configuration. (G)
FIG. 3 shows a configuration in which detection sensors are provided on upper and lower surfaces, and FIG. 4H shows a configuration in which detection sensors are provided on lower surfaces.

FIG. 8 shows a circuit example of an oil leak detection monitor.

FIG. 9A is a cross-sectional view showing an overlapping structure of FRP (fiber reinforced composite material), and FIG. 9B is another sectional view showing an overlapping structure of FRP (fiber reinforced composite material);
(C) is another sectional view showing an overlapping structure of FRP (fiber reinforced composite material).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Underground tank 2 Lubrication pipe 3 Lubrication pipe 4 Ventilation pipe 5 Liquid level gauge 6 Lubrication port 7 Instruments, such as a meter and a pump 8, 9 Valve 10 Vent port 11, 12 Detection sensor 13 Electric transmission cable 14 Oil leak detection monitor 16 Steel Piping 17 FRP (Fiber Reinforced Composite) 18 Lead wire (conductive wire) 19 Primer 20a to 20l Comparator 21 OR gate 22a, 22b Insulation material 23 Conduit tube 25 Butt

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[Procedure amendment]

[Submission date] October 28, 1999 (1999.10.
28)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

[Correction contents]

Next, an airtight test of the gap (small space) is performed. This test is performed by inserting an injection needle for an airtight test into an FRP (fiber reinforced composite material) 17 and injecting test air into the gap. After the airtight test, the pierced injection needle is pulled out, and a FRP (fiber reinforced composite material) 17 is overlaid and adhered to the portion. Thereafter, ultraviolet rays are irradiated to cure the FRP (fiber reinforced composite material) 17.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0062

[Correction method] Change

[Correction contents]

The pipe from which the plastic film is peeled as described above is particularly referred to as a double pipe, and the pipe to which the plastic film is directly adhered without being peeled may be defined as a double shell pipe .

Claims (11)

[Claims] 1. A double pipe structure comprising: a pipe; and a fiber reinforced composite material that is provided on an outer periphery of the pipe and that prevents a leakage material from the pipe from leaking outside. 2. A pipe, a fiber-reinforced composite material which is provided on an outer periphery of the pipe, and prevents a leakage material from the pipe from leaking to the outside, and is disposed between the pipe and the fiber-reinforced composite material. A double piping structure comprising: a provided lead wire for guiding the leaking material; and a sensor for detecting the leaking material disposed between the pipe and the fiber-reinforced composite material. 3. The double piping structure according to claim 1, wherein the leaking material is oil. 4. The double piping structure according to claim 1, wherein the leaking material is a gas. 5. The double-pipe structure according to claim 2, wherein the conductor is provided along a lower surface of the pipe. 6. The double-pipe structure according to claim 2, wherein the conductor is disposed along upper and lower surfaces of the pipe. 7. The double-pipe structure according to claim 2, wherein the conductor is arranged in a mesh on the peripheral surface of the pipe. 8. The double pipe structure according to claim 2, wherein the conductor is spirally disposed on a peripheral surface of the pipe. 9. The double piping structure according to claim 2, wherein the detection sensor is provided on a lower surface of a most downstream portion of the piping. 10. The double pipe structure according to claim 2, wherein a plurality of said detection sensors are provided on a lower surface of said pipe. 11. The double piping structure according to claim 2, wherein a plurality of said detection sensors are provided on a peripheral surface of said piping.