JP2007269323A - Underground tank and piping construct - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain such a constitution as to be capable of preventing corrosion, even in the case of an underground tank and a piping construct in an environment where water is easily accumulated in a protective bulkhead. <P>SOLUTION: In the underground tank and the piping construct, a protective bulkhead is provided on the top surface of the cylindrical part of the steel-made underground tank, and the steel piping is provided in a space which is defined by the protective bulkhead. An electrolyte exists in the space which is defined by the protective bulkhead; and a sacrificial anode which is composed of a metal ignoble in potential more than steel is provided on the top surface of the cylindrical part of the underground tank in a state of being brought into contact with the electrolyte. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an underground tank and a pipe structure used in, for example, a gas station.

The underground tank and piping structure provided in a gas station etc. have the following configuration. A rectangular protective partition (protector) is provided on the upper surface of a cylindrical portion of a steel underground tank buried underground, and a steel rising pipe and a horizontal pipe are provided in a space defined by the protective partition. This protective partition wall is provided to protect the pipe connection portion from the pressure of the soil around the underground tank, so-called earth pressure, and to ensure the ease of maintenance.

Because underground tanks are made of steel, they are at risk of natural corrosion and corrosion due to electrical or chemical conditions. If there is a hole in the underground tank due to the progress of corrosion, it will contaminate the soil and cause environmental destruction.
JP2006-076663

As a method to prevent corrosion of underground tanks, recently, an electrode is embedded in the vicinity of the underground tank, a weak current is passed from this electrode, and an external power source method that uses a sacrificial electrode or an external power supply method that protects the underground tank from corrosion. Corrosion prevention measures are being adopted. However, even with this method, the protector inside the upper part of the underground tank is shielded from the outside by a protective partition, and the anticorrosion effect of the above-described external power source method or galvanic anode method cannot be expected. In addition, the lower side of the space defined by the protective partition wall has a very high degree of sealing, and water tends to accumulate inside. That is, since it is always in contact with moisture and is in an environment where corrosion is accelerated, there is no fear that corrosion is likely to occur.
Therefore, the present invention provides an underground tank and a piping structure that can prevent corrosion even if the underground tank and the piping structure are placed in such an environment.

The underground tank and the pipe structure according to claim 1, wherein a protective partition is provided on the upper surface of the cylindrical portion of the steel underground tank, and the steel tank is provided in a space defined by the protective partition. In the piping structure,
An electrolyte is present in a space defined by the protective partition wall, and a sacrificial anode made of a metal having a lower potential than steel is provided on the upper surface of the cylindrical portion of the underground tank in contact with the electrolyte. .
The underground tank and piping structure according to claim 2, wherein a protective partition is provided on the upper surface of the cylindrical portion of the steel underground tank, and the steel tank is provided in a space defined by the protective partition. And in the piping structure,
An electrolyte is present in a space defined by the protective partition wall, and a sacrificial anode made of a metal having a lower potential than steel is provided in the pipe in a state in contact with the electrolyte.
The underground tank and the pipe structure according to claim 3, wherein a steel protective partition is provided on the upper surface of the cylindrical portion of the steel underground tank, and the steel pipe is installed in a space defined by the steel protective partition. In the underground tank and piping structure provided with
An electrolyte is present in a space defined by the steel protective partition wall, and a sacrificial anode made of a metal having a lower potential than steel is provided in the steel protective partition wall in contact with the electrolyte. To do.
According to a fourth aspect of the present invention, there is provided an underground tank and piping structure according to the first to third aspects, wherein the electrolyte is composed of water, earth, or a gel substance.

  According to invention of Claim 1, corrosion of the cylindrical part surface (upper surface) surrounded by the protective partition of the steel underground tank can be prevented. According to Claims 2 and 3, the occurrence of corrosion of the piping or the steel protective partition can be prevented.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a steel underground tank in which both sides of a cylindrical shape are closed by end plates (the whole view is omitted). On the upper surface of the cylindrical portion of the underground tank 1, a rectangular protector guide 2 made of steel and surrounding the periphery in four horizontal directions is provided by welding. The protector guide 2 is provided with a protector 3. In the internal space determined by the protector 3, a rising pipe 4 and a horizontal pulling pipe 5 rising from the underground tank 1 are provided.

  In this embodiment, the underground tank 1 and the pipe 2 are provided with a sacrificial anode 6 made of a metal whose potential is lower than that of steel, in the embodiment, a mass of magnetism, via wiring. Further, the space in the protector 3 is filled with at least a sufficient amount of electrolyte to be buried in the sacrificial anode 6. Usually, water is used as the electrolyte, but the electrolyte is not necessarily limited thereto, and may be soil containing water, sand, earth and sand, or a gel-like substance.

  Example 2 shows a simple attachment structure of lead wires to piping. A second embodiment will be described with reference to FIGS. A terminal 8 is provided at the tip of the lead wire 7 connected to the sacrificial anode 6. As shown in the enlarged view of FIG. 3, a bolt 9 that connects the flanges 4 </ b> A of the rising pipe 4, a nut 10 that is screwed to the bolt 9, and an upper nut 11 that is separately provided on the nut 10 are provided. And the terminal nut 8 are fixed between the upper nut 11 and the upper nut 11. Thereby, the sacrificial anode 6 can be attached easily and firmly. FIG. 4 shows a plan view.

  Example 3 shows a structure in which a sacrificial anode is directly attached to the underground tank 1, the rising pipe 4 and the horizontal pulling pipe 5. In FIG. 5, a sacrificial anode 6 is provided on one or both of the rising pipe 4 and the horizontal pulling pipe 5 so as to surround a half of the outer periphery, and the sacrificial anode 6 is fixed by band means 12.

  Example 4 shows an example in which the sacrificial anode 6 is directly attached to the underground tank 1. As shown in FIG. 6, metal protrusions are provided on the lower surface of the sacrificial anode 6, which is a mass of magnet, so as to come into close contact with the surface of the magnet plate 13 and the underground tank 1. FIG. 7 shows a state of being attached to the upper surface of the underground tank 1.

  In the above-described embodiments, the sacrificial anode 6 is attached to the underground tank 1, the rising pipe 4, and the horizontal pulling pipe 5. However, the sacrificial anode 6 may be connected to the inner surface of the protector 3 itself. Thereby, corrosion prevention of protector 3 itself can be aimed at.

  In this embodiment, the sacrificial anode 6 is provided inside the protector 3. However, as another embodiment, the protector is filled with an electrolyte, an insoluble electrode (made of titanium) is provided, and this electrode is connected to a DC electrode. And it may be made to prevent the occurrence of corrosion of the upper surface of the underground tank, the rising pipe 4, the horizontal pulling pipe 5, and the protector 3 by continuously passing a current from the electrode to the inside of the protector 3.

  In the above description, an example of application to an underground tank of a gas station has been shown, but the present invention may be applied to a general oil handling station, a private gas station, an underground tank of a factory, and a piping structure.

It is sectional drawing which shows the 1st Example of this invention. It is a partial side view which shows the 2nd Example of this invention. It is a partially expanded side view which shows the 2nd Example of this invention. It is a partial top view which shows the 2nd Example of this invention. It is a partial top view which shows the 3rd Example of this invention. It is a partial top view which shows the 4th Example of this invention. It is a partial top view which shows the 4th Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Underground tank 2 Protector guide 3 Protector 4 Standing piping 5 Horizontal piping 6 Sacrificial anode 7 Lead wire 8 Terminal 9 Bolt 10 Nut 11 Upper nut 12 Band means 13 Magnet plate 14 Metal protrusion

Claims (4)

In the underground tank and piping structure in which a protective partition is provided on the upper surface of the cylindrical portion of the steel underground tank, and in addition, a steel pipe is provided in the space defined by the protective partition,
An underground tank characterized in that an electrolyte is present in a space defined by the protective partition, and a sacrificial anode made of a metal having a lower potential than steel is provided on the upper surface of the cylindrical portion of the underground tank in contact with the electrolyte, and Piping structure. In the underground tank and piping structure in which a protective partition is provided on the upper surface of the cylindrical portion of the steel underground tank, and in addition, a steel pipe is provided in the space defined by the protective partition,
An underground tank and piping structure characterized in that an electrolyte is present in a space defined by the protective partition wall, and a sacrificial anode made of a metal having a lower potential than steel is provided in the pipe in contact with the electrolyte. . In the underground tank and the pipe structure in which a steel protective partition is provided on the upper surface of the cylindrical portion of the steel underground tank, and in addition, a steel pipe is provided in a space defined by the steel protective partition,
An electrolyte is present in a space defined by the steel protective partition wall, and a sacrificial anode made of a metal having a lower potential than steel is provided in the steel protective partition wall in contact with the electrolyte. Underground tanks and piping components. 4. The underground tank and the piping structure according to claim 1, wherein the electrolyte is water, soil, or a gel-like substance.

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