JP2018179759A - Defect detection device of underground piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relate to a defect detection device of underground piping which can quickly detect a defect of the underground piping when, in particular, a disaster or the like occurs, related to the defect detection device of the underground piping arranged at equipment for storing gasoline and oils such as a gas station.SOLUTION: A defect detection device of underground piping having a double-piping structure composed of inside piping for oils including gasoline which is embedded in the ground, and outside piping having a prescribed clearance between the inside piping and itself, and covering the inside piping comprises: a pressurizer connected to the clearance, and applying constant pressure to the clearance; a detector which uses the pressurizer, and confirms whether or not the pressure is lowered after the constant pressure is applied to the clearance; and a control part for determining that a defect occurs at the piping when the lowering of the pressure is confirmed by the detector.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a defect detection apparatus for a buried pipe disposed in a facility such as a gas station or the like for storing gasoline and oils, and in particular, a buried pipe that enables rapid detection of a defect in the buried pipe when a disaster or the like occurs. Defect detection apparatus for

  Today, soil pollution due to oil and other oil leaks has become a social problem. Such oil leaks occur due to long-term use of underground tanks and buried pipes for storing oils such as gasoline and the like, causing corrosion and pitting of the tanks and pipes. In this case, the pipe is a steel pipe (steel pipe), and for example, the outer surface of the pipe is coated or coated to prevent corrosion. In the case of a buried tank, a method disclosed in Patent Document 1 is also proposed.

Unexamined-Japanese-Patent No. 2003-261195

  However, if a large-scale disaster such as an earthquake occurs, it is imagined that the tank and buried piping will be cracked and many facilities will be damaged at the same time. In this case, defect inspection of the tank and buried piping quickly It is necessary to do. In such a case, the buried tank is generally provided with a liquid level gauge. For example, even if the tank is cracked and an oil leak occurs, the liquid level gauge can easily know that the tank has a defect such as a crack. Can. On the other hand, in the case of buried piping, even if a crack occurs, the occurrence of the crack can not be immediately detected.

  For example, when gasoline is injected into a tank via a buried pipe or when gasoline is supplied from a tank, even if gasoline leaks from the pipe, it is part of the gasoline and it is detected that the pipe is cracked It is not possible.

  Then, in order to solve the above-mentioned subject, the present invention can detect these defects quickly even if a crack occurs in a buried tank due to an earthquake etc. and such a problem occurs simultaneously in many facilities at the same time An object of the present invention is to provide a buried pipe defect detection apparatus. In addition, even if the pipe has been corroded or pitted due to its use for many years and grows into a corroded hole or pitted hole due to an earthquake or the like, the corroded hole or corroded hole generated similarly can be detected promptly. An object of the present invention is to provide a buried pipe defect detection apparatus.

  In order to solve the above-mentioned subject, the present invention is piping of oil containing gasoline buried under the ground, and it is an outer side piping which formed predetermined gaps in inner side piping and this inner side piping, and was covered by inner side piping. And a pressurizer which is connected to the gap and applies a constant pressure to the gap, and after applying a constant pressure to the gap using the pressurizer, A defect of the buried piping comprising: a detector for confirming whether the pressure is reduced, and a control unit for judging that the piping has a defect when the reduction of the pressure is confirmed by the detector. Provided is a detection device.

  In addition, after the control unit applies a constant pressure to the gap, it waits for the passage of a fixed time to check whether the pressure decreases or not, detects a defect in the pipe, and detects the crack in the pipe. For the purpose of discovering the Furthermore, defect detection is characterized by using a defect inspection port provided in advance in the outer pipe of the double pipe.

  According to the present invention, it is possible to easily inspect a buried pipe, and for example, when a large disaster such as an earthquake occurs and many facilities such as a gas station are inspected for defects such as cracks. It is possible to inspect buried piping extremely quickly.

BRIEF DESCRIPTION OF THE DRAWINGS It is a system block diagram explaining the defect detection apparatus of the buried piping of this embodiment. It is a figure which shows the cross-section which contains an underground tank and an oil supply pipe. It is a perspective view of a lubrication pipe. It is the figure which expanded the vicinity of the oil supply port located in the front-end | tip of an oil supply pipe | tube. It is an external view of the pressurizer (air compressor) which applies predetermined pressure to a crevice. It is a flowchart explaining the processing procedure of defect inspections, such as a crack of an oil supply pipe which is underground piping. It is a figure which shows the state which attached the air injection pipe of the pressurizer to the defect inspection part provided in the oil supply pipe | tube. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a view for explaining a defect detection apparatus for a buried pipe according to the present embodiment, which is applied to a pipe when oil (gasoline) is stored in a buried tank. In this embodiment, an example of a buried pipe for supplying gasoline to a tank buried underground in a gas station and for supplying gasoline from the tank to a vehicle is shown as the buried pipe.

  In the figure, the tank 1 is stored with an oil supply pipe 2 for supplying oil (gasoline), an oil supply pipe 3 for supplying oil (gasoline) from the tank 1, a vent pipe 4 for ventilating the tank 1, and the tank 1 A level gauge 5 is provided to measure the level of oil (gasoline). The tank 1 is buried at a predetermined depth from the ground surface, and concrete 18 is installed on the tank 1.

  An oil inlet 6 is provided on the surface of the oil pipe 2, and oil (gasoline) is oiled from the oil inlet 6. Further, equipment 7 such as a measuring instrument and a pump is provided on the surface of the fuel supply pipe 3 so as to suck oil (gasoline) from the tank 1 and measure oil (gasoline) to be sucked. Furthermore, the oil supply pipe 2 is provided with a valve 8, and the oil supply pipe 3 is provided with a valve 9, and when the tank 1 is repaired / renovated, the valves 8 and 9 are closed. A vent 10 is provided in the vent pipe 4 to discharge the gas generated in the tank 1.

  The tank 1 of this example is a so-called double shell tank, and has a structure in which FRP (Fiber-Reinforced Composite) is provided inside the steel material of the tank which is a base (not shown) via a three-dimensional cloth such as a primer and honeycomb board. It is.

  FIG. 2 particularly shows a cross-sectional structure including the tank 1 and the oil supply pipe 2. As described above, the oil supply pipe 2 is provided with an oil supply port 6, oil (gasoline) is supplied from the oil supply port 6, and oil (gasoline) is stored in the tank 1 through the oil supply pipe 2. As shown in the figure, the oil supply pipe 2 has a double structure, and has a structure in which a primary pipe 12 made of resin is used as a base pipe and a secondary pipe 13 made of the same resin is covered with the primary pipe 12. Here, the feature of the double structure of the oil supply pipe 2 of this example will be further described.

  FIG. 3 is a perspective view of the oil supply pipe 2 of this embodiment. As described above, the oil supply pipe 2 has the same resin secondary pipe 13 covered with the resin primary pipe 12, and a gap 14 with a predetermined width between the primary pipe 12 and the secondary pipe 13. It is formed. For example, an oil leak detection line (not shown) is disposed in the gap 14. The primary piping 12 and the secondary piping 13 are not limited to thermoplastic resins such as polyethylene and polyamide, and thermosetting resins such as phenol resin and epoxy resin can be used as materials.

  The oil leak detection line for detecting oil (gasoline) leaks is provided in the oil supply pipe 2, and this oil leak detection line extends to the oil leak detection monitor 17 via the electric transmission cable 16 as shown in FIG. 2. It is extended.

  FIG. 4 is an enlarged view of the vicinity of the oil supply port 6 located at the tip of the oil supply pipe 2 and is an enlarged view of a portion A of FIG. 2 described above. As shown in FIG. 4, a defect inspection unit 20 for inspecting a crack or the like generated in the piping of the oil supply pipe 2 is provided on the side surface in the vicinity of the oil supply port 6. Normally, a lid 21 is attached to the defect inspection unit 20, and when conducting a piping inspection of the oil supply pipe 2, the lid 21 fastened to the defect inspection unit 20 is opened, and a pressurizer described later is attached. Apply a set pressure.

  FIG. 5 is an external view of a pressure device (air compressor) for applying a predetermined pressure to the gap 14. As shown in the figure, the pressurizer 22 includes an air gauge 23, a drive switch 24, an air injection pipe 25, and a power supply line 26. The air gauge 23 has a function of setting the pressure to be applied to the gap 14 formed between the primary pipe 12 and the secondary pipe 13, and the gap from the pressurizer 22 through the air injection pipe 25 by turning on the drive switch 24. Air is supplied to. The power supply line 26 is connected to an outlet (not shown) at the time of a pipe inspection to supply power to the pressurizer 22.

In the above configuration, the procedure of defect inspection in this example will be described below.
FIG. 6 is a flow chart for explaining the processing procedure of inspection for defects such as cracks in the oil supply pipe 2 which is the above-mentioned buried pipe. In addition, the inspection of this example is a defect inspection of piping which a large disaster, such as an earthquake generate | occur | produces, for example as a premise, and an operator goes to the installation of a gas station etc. of the area concerned.

  First, the operator checks the defect inspection unit 20 provided in the oil supply pipe 2 and opens the lid 21 attached to the defect inspection unit 20 (step (hereinafter, indicated by S) 1). Then, in order to attach the brought-in pressurizer 22 to the defect inspection unit 20, the air injection pipe 25 is extended and attached to the defect inspection unit 20 (S2). FIG. 7 shows a state in which the air injection pipe 25 of the pressurizer 22 is attached to the defect inspection unit 20 provided in the oil supply pipe 2.

  Next, the drive switch 24 provided in the pressurizer 22 is turned on to drive the pressurizer 22, and the supply of air to the gap 14 is started via the air injection pipe 25 (S3). By the supply of air to the gap 14, the pressure in the gap 14 gradually increases. During this time, the operator visually checks the above-mentioned air gauge 23 provided in the pressurizer 22 and determines whether the gap 14 reaches a preset pressure. It judges (S4). Then, when the pressure in the gap 14 rises and the gap 14 reaches a preset pressure (YES in S4), the drive switch 24 is turned off (S5). If the gap 14 has not reached the preset pressure (NO in S4), the supply of air to the gap 14 is continued, and the gap 14 continues until it reaches the preset pressure (ST3 →). ST4 is YES).

  Next, the air gauge 23 is checked to determine whether the pressure in the gap 14 is reduced (S6). For example, the air gauge 23 is checked for a predetermined time (for example, several minutes), and if there is no drop in pressure, it is determined that the pressure in the gap 14 is maintained. It is judged that there is nothing (S6 is YES, S7). On the other hand, if the numerical value of the air gauge 23 decreases within a predetermined time, it is determined that a crack is generated in either the primary pipe 12 or the secondary pipe 13 forming the gap 14 and the pressure in the gap 14 is reduced. (S6 is NO), it is determined that the oil supply pipe 2 has a defect (S8).

  As described above, according to the inspection apparatus of the buried pipe of the present embodiment, the inspection of the oil supply pipe 2 and the like can be easily performed easily. For example, a large disaster such as an earthquake occurs, and many facilities such as a gas station etc. When inspecting whether a defect such as a crack has occurred, the inspection of buried piping can be performed extremely quickly. That is, the apparatus for inspecting a defect in a buried pipe according to the present embodiment only brings the pressurizer 22 into a gas station facility and attaches the pressurizer 22 (air injection pipe 25) to the defect inspection unit 20 provided in the buried pipe of the oil pipe 2 or the like. Inspection of cracks and the like can be performed, and defect inspection of buried piping can be performed extremely simply and rapidly.

  In the above description, although the example of the oil supply pipe 2 has been described, similarly for the oil supply pipe 3 disposed in the same facility, the pressurizer 22 (air injection pipe 25) is provided in the defect inspection unit provided in the oil supply pipe 3. Inspection of a crack etc. can be performed only by attaching), and inspection of piping can be performed similarly about the buried piping in other facilities.

DESCRIPTION OF SYMBOLS 1 ... Tank 2 ... Oil supply pipe 3 ... Oil supply pipe 4 ... Ventilation pipe 5 ... Liquid level gauge 6 ... Oil supply port 7 ... Equipments, such as a pump 8, 9. Valve 10 · · Air vent 11 · · · Concrete 12 · · Primary piping 13 · · Secondary piping 14 · · Gap 16 · · Electrical transmission cable 17 · · Detection monitor 20 · · Defect inspection portion 21 · · Lid 22 · · · Pressurizer 23 ··· Air gauge 24 · · Drive switch 25 · · Air injection tube 26 · · Power wire

Claims (7)

A double piping structure comprising an oil pipe including gasoline buried underground and having an inner pipe and an outer pipe formed by forming a predetermined gap in the inner pipe and covering the inner pipe. And
A pressurizer connected to the gap to apply a constant pressure to the gap;
A detector that uses the pressurizer and applies a constant pressure to the gap and then checks whether the pressure decreases or not;
A control unit that determines that the pipe has a defect when the pressure drop is confirmed by the detector;
A buried pipe defect detection apparatus comprising:   The control unit, after applying a constant pressure to the gap, waits for an elapse of a constant time, confirms whether the pressure decreases or not, and detects a defect in the pipe. The buried pipe defect detection apparatus described above. The said defect detection is performed for the purpose of discovery of the crack which arose in the said piping, The defect detection apparatus of the buried piping of Claim 1 or 2 characterized by the above-mentioned. The said defect detection is performed using the defect inspection port previously provided in the outer side piping of the said double piping, The defect detection apparatus of the buried piping of Claim 1, 2 or 3 characterized by the above-mentioned. 5. The double-layered underground piping is disposed in piping equipment of a gas station, and is used for lubricating and refueling gasoline to the underground tank. Buried piping defect detection system.   A buried double pipe, which is a pipe of oil containing gasoline buried underground and which comprises an inner pipe and an outer pipe formed with a predetermined gap in the inner pipe and covered with the inner pipe. Using a pressure device connected to the gap and applying a constant pressure to the gap, and by applying a constant pressure to the gap, a detector that checks whether the pressure decreases or not A method for detecting a defect in a buried pipe, comprising determining that the pipe has a defect when the pressure drop is confirmed.   7. The apparatus according to claim 6, wherein the control unit, after applying a constant pressure to the gap, waits for a lapse of a predetermined time to check whether the pressure decreases or not, and detects a defect in the pipe. Buried piping defect detection method described.

Images