JPH0130396Y2 - - Google Patents

Description

[Detailed explanation of the idea]

Purpose of invention

[Industrial application field]

The present invention relates to a leak detection mechanism at a welded portion when piping is fixed to a metal wall of a fluid container by welding. Here, the term "piping" collectively refers to pipes, supports, etc. provided on the walls of the container (including not only the side walls but also the ceiling and bottom).

[Conventional technology]

For example, in nuclear installations, containers made of concrete structures lined with stainless steel are used to contain radioactive fluids.
Leakage of the contained fluid must be prevented as much as possible, and if a leak occurs, it must be known immediately. In particular, it is important to detect leaks in areas where piping is welded to the container wall. For this purpose, various leakage detection mechanisms have been proposed and put into practice. One method is to join a seat plate that supports the piping to the metal lining, place a backing metal on the back side of the joint between the seat plate and the lining, weld the joint to the backing metal, and weld the weld line. There is a lining tank in which a ring-shaped space is provided in the outer backing metal, and the leakage detection piping is led out from there (Special Publications Publication in 1973).
−30278). This means there is no time delay in detection,
However, it is not possible to prevent leakage from penetrating from the annular space that collects leakage through the gap between the backing metal and the lining. Since the space is only outside the weld line between the lining and the seat plate,
It was still not perfect in that it was difficult to detect when leakage occurred inward.

[Problem that the invention attempts to solve]

This invention solves these problems, and even in the unlikely event that a leak occurs, welding leakage can be detected without delay, and the leakage detection mechanism not only immediately identifies the leakage area, but also completely prevents leakage from penetrating. I will provide a. Structure of the idea

[Means to solve the problem]

The leak detection mechanism of the present invention typically detects leaks in a structure in which piping 3 is fixed to a metal wall 2 of a fluid container via a seat plate 4 and a leak detection member 1, as shown in FIG. The detection member 1 is approximately annular and is located behind and welded to the welded portion 8A of the metal wall 2 and seat plate 4, and its outer periphery is seal welded 8B to the back surface of the metal wall. It is characterized in that it has a circular groove 14 on the outside of the welded part, a leakage discharge pipe 6 is led out from this groove, and a leak detection means 7 is provided in the pipe line. The annular groove may be provided not only on the outside of the welded portion but also on the inside as shown. In addition, the welded portion 8A is connected to the metal wall 2 and the seat plate 4 as shown in the figure.
In addition to welding the leak detection member 1 and the leak detection member 1 together, welding is also provided between the metal wall 2 and the member 1 and between the member 1 and the seat plate 4. In other words, the seat plate is welded through the member 1. is welded to the metal wall 2, and the welded part 8A
It may be divided into two parts. Typical examples of the leak detection member 1, which is a characteristic element constituting the above mechanism, are shown in FIGS. 2 and 3.
As shown in the figure. This example also has an annular groove 15 on the inside.

[Effect]

By configuring as described above, leakage from the welded part can be almost completely prevented, but in the unlikely event that there is a leakage at the welded part 8A between the leak detection member 1 and the metal wall 2, the leaked material will be It exits into the annular groove 14 or 15 of the leak detection member 1. Those that appear at 15 pass through connecting path 16 and gather at 14. Even when the welded portion 8A is divided into two parts as described above, leakage materials similarly collect in the grooves 14 and 15. The leakage material is thus led out through the discharge pipe 6 and detected by a leak detection means 7, for example an eyeglass. Since this leaked material is sealed by the welded portion 8B, it will not seep out.

【Example】

The example shown in FIG. 1 is a leakage detection mechanism for horizontal piping, and in addition to the above, a sleeve 5 for protecting the piping is welded to the back side of the leakage detection member 1, and the piping 3 is Annular weirs 9 and 10 are provided on the outside and on the inside of the sleeve 5. If there is a leak at the welds 8C and 8D between the seat plate 4 and the pipe 3, the liquid leakage will be blocked by these weirs 9 and 10, and the annular groove 14,
15, and is discharged. FIG. 4 shows another embodiment of the present invention, and the sleeve 5 can also be attached to the back side of the seat plate 4 as shown in this figure. In this case, the pipe 3, seat plate 4, sleeve 5 and weirs 9 and 1
Also from the space formed by 0, the leakage discharge pipe 6
It is sufficient to provide a flow path for leakage to. Even when the support is fixed to the wall of the fluid container, leakage from the welded portion can be prevented and detected using a similar configuration as described above. Effects of the invention Although the leakage detection member used in the invention has a simple structure as described above, it is possible to create a leak-free structure. In the event of a leak, you can immediately locate the leak and take immediate action. As mentioned in the introduction, the present invention is most meaningful when applied to radioactive waste storage tanks or nuclear fuel storage tanks of nuclear power facilities, but it is also useful for other tanks included in chemical plants. Further, the fluid is not limited to liquid, but may be gas or liquefied gas such as LPG, and the present invention can be applied by using a gas detection tube as the leakage detection means.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an example of the leak detection mechanism of the present invention. 2 and 3 show the leak detection member shown in FIG. 1, with FIG. 2 being a plan view and FIG. 3 being a sectional view. FIG. 4 shows another example of the leakage detection mechanism of the present invention.
It is a sectional view similar to the figure. 1... Leak detection member, 2... Side wall of the container, 3
...Piping, 4...Seat plate, 5...Sleeve, 6...
Leakage discharge pipe, 7...Leakage detection means, 8A, 8
B, 8C, 8D...Welded parts.

Claims (1)

[Claims for Utility Model Registration] (1) In a structure in which piping 3 is fixed to a metal wall 2 of a fluid container via a seat plate 4 and a leakage detection member 1, the leakage detection member 1 is approximately annular. It is located behind the welded portion 8A of the metal wall 2 and seat plate 4 and is welded thereto, and its outer periphery is seal welded 8B to the back surface of the metal wall.
A fluid leakage detection mechanism for a welded part, characterized in that the welded part has an annular groove 14 outside the welded part, a leakage discharge pipe 6 is led out from this groove, and a leakage detection means 7 is provided in the pipe. (2) The fluid leakage detection mechanism according to claim 1, which also has an annular groove 15 inside the welded portion of the leakage detection member 1. (3) The sleeve 5 is welded to the back side of the leak detection member 1, and annular weirs 9 and 10 are provided on the outside of the piping 3 and the inside of the sleeve 5, and the piping, seat plate,
The fluid leakage detection mechanism according to claim 1, wherein a flow path for leakage from the space formed by the sleeve, these weirs, and the leakage detection member to the leakage discharge pipe 6 is provided. (4) A sleeve 5 is welded to the back side of the seat plate 4, and an annular weir 9 is formed between the outside of the piping 3 and the inside of the sleeve 5.
and 10, and a flow path for leakage from the space formed by the piping, the seat plate, the sleeve, and these weirs to the leakage discharge pipe 6 is provided. Fluid leak detection mechanism. (5) Scope of utility model registration claim 1 that applies to tanks for storing radioactive liquid waste or nuclear fuel
The fluid leakage detection mechanism according to any one of Items 1 to 4.