JPS60216238A - Fluid leakage detection mechanism - Google Patents

Abstract

PURPOSE:To enable immediate handling of any leakage in a fluid container by arranging a through port slighly larger than the outer diameter of a piping to be arranged in a leakage detecting member on a disc and a groove thereoutside to be made to communicate with each other. CONSTITUTION:For example, when a piping 3 is installed on a metal wall 2 of a fluid container in a nuclear power equipment or the like through a leakage detecting member 1, a through port 11 slightly larger than the outer diameter of the piping 3 is provided in the leakage detecting member 1 and a projection 12 and grooves 14 and 15 on the circumference thereof. The grooves 14 and 15 are so constructed to communicate with each other through a path 16. When the piping 3 is fixed, a seal welding 8C is applied between the projection 12 of the leakage detecting member 1 and the piping 3 and seal welding 8A and 8B between the projection and the metal wall 2. Thus, a sufficient joining can be done. But in case of any leakage, a matter being leaked reaches the leakage detection means 7 from the groove 14 or from the groove 15 through the path 16 and thereby, the leakage can be handled immediately.

Description

[Detailed description of the invention]

1 "No pressure"

INDUSTRIAL APPLICATION FIELD 1 The present invention relates to a leak detection mechanism at a welded portion when a pipe is fixed to a metal wall of a fluid container by welding. [Prior Art] For example, in nuclear power facilities, a container made of a concrete structure lined with stainless steel is used to contain fluid containing radioactive substances. 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 leakage at the part where piping for fluid entry and exit is welded to the wall of the container. 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 that weld line. Provide an annular space in the outer backing metal,
There is a lining tank from which leak detection piping is derived (
Special Publication No. 56-30278). This is excellent in that there is no time delay in detection and it is easy to identify the leakage area, but since the annular space that collects leakage is outside the weld line between the lining and the seat plate, It was still not perfect in that it was not possible to detect inward leakage, and it was not possible to prevent leakage from penetrating from this space through the gap between the backing metal and the lining. [Problems to be Solved by the Invention] The present invention solves these problems, has a simple structure, can perform sufficient and reliable welding, and even if leakage occurs, it can detect leakage from the welded part. To provide a leakage detection mechanism which can be performed without delay, allows immediate identification of a leakage part, and prevents leakage from penetrating. 11 sad ILJL

[Means to solve the problem]

The leakage detection mechanism of the present invention is a structure in which piping is fixed to a metal wall of a fluid container via a leakage detection member, and the leakage detection member is approximately disk-shaped, and the leakage detection mechanism is installed in a structure in which piping is fixed to a metal wall of a fluid container through a leakage detection member. It has a through hole with a diameter sufficient for fixing, and the circumference of this through hole forms an annular protrusion with a height approximately equal to the thickness of the metal wall of the fluid container, and the inner surface of the through hole and the annular protrusion form a Each of the outer sides has an annular groove, and these grooves communicate with each other through at least one passage, and the metal wall of the fluid container and the leak detection member are connected to the inner surface of the former and the outer periphery of the latter annular protrusion. The outer surface of the former and the outer periphery of the latter are joined by seal welding, and a leakage discharge pipe is led out from the groove on the outside of the annular protrusion.
It is characterized in that the conduit is equipped with a leak detection means.

[Function 1] A characteristic element constituting the above mechanism is a leakage detection member, and typical examples of the leakage detection member are shown in FIGS. 1 and 2. The leakage detection member 1 has a circular disk shape, and has a through hole 11 in its center with a diameter sufficient to allow the pipe to be passed through and fixed, that is, a diameter slightly larger than the outer diameter of the pipe. The periphery of this through hole forms an annular protrusion 12 having a height approximately equal to the thickness of the metal wall of the fluid container. There are annular grooves 15 and 14 on the inner surface of the through hole 11 and on the outer side of the annular projection 12, respectively, and these grooves communicate with each other through at least one passage 16. The groove 18 roughly on the back side of the through hole 11 is
This is for inserting an O-ring. [Example] Using this leakage detection member 1, a pipe is attached to the side wall of a fluid container, and a leakage detection mechanism at the welded portion is constructed as shown in FIG. 3. That is, groove surfaces are provided on the outer periphery of the annular protrusion of the leak detection member 1 and on the metal wall of the container, respectively, and these are joined over the entire abutting surfaces by seal welding 8A as shown. As a result, sufficient fusion welding can be performed without creating a gap on the back side of the welded part. As shown in the figure, the metal wall 2 and the leakage detection member 1 are also joined by seal welding 8B at the outer surface of the bent member and the outer circumference of the latter. Grooves are provided at the end of pipe 11 and on the outside of the end of the pipe, respectively, and seal welding 8C is performed as shown in the figure.
This seal weld 8C connects the groove surface to the annular groove 15 in the through hole.
It is best to create a fused portion with no gaps by providing it close to the . A sleeve 5 for protecting this piping is attached to a welded part 8 to the leak detection member 1.
Join at D. 8A and 8G are group welds, and 8B and 80 are fillet welds. 1li18 is provided with an O-ring 9. By configuring as described above, leakage from the welded portion can be almost completely prevented, but in the unlikely event that the leakage detection member 1 and the side wall 2
If there is a leak in the welded part 8A, the leaked material will enter the annular groove 14 of the leak detection member 1, and the leaked material will be led out through the discharge pipe 6 and leaked to the leak detection means, such as an eyeglass. Detected by 7. Since this leaked material is sealed by the welded portion 8B, it will not leak out. If there is a leak at the welded portion 8C between the leak detection member 1 and the pipe 3, the leakage material collected in the annular groove 15 passes through the flow path 16 and moves to the annular groove 14, so that it is similarly detected. This leaked material is also prevented from seeping out by the O-ring 9. 11Δ11 The leakage detection member used in the present invention has a simple structure as described above, and welding between the metal wall of the container and the metal wall is performed by providing a groove surface and performing welding without any gaps. Fusion is ensured and a leak-free structure can be created. In the event of a leak, you can immediately locate the leak and take immediate action. As mentioned at the outset, the present invention is most meaningful when applied to radioactive waste storage tanks or nuclear fuel storage tanks of nuclear facilities, but is also useful for other tanks included in chemical plants. Further, the fluid is not limited to a liquid, but may be a gas or a liquefied gas such as LPG, and can be applied by using a gas detection tube as a leakage detection means.

[Brief explanation of the drawing]

1 and 2 show an example of a leakage detection member that constitutes a part of the leakage detection mechanism of the present invention.
The figure is a plan view, and FIG. 2 is a sectional view. FIG. 3 is a sectional view of the leakage detection mechanism when piping is attached to the side wall using the leakage detection member shown in FIGS. 1 and 2. FIG. 1...Leakage detection member 2...Side wall of container 3...Piping 5...Sleeve 6...Leakage discharge pipe 7...Leakage detection means 8A, 8B, 8C, 8D... Welding patent applicant JGC Corporation agent Patent attorney Souo Suga Figure 2

Claims (3)

[Claims] (1) In a structure in which piping is fixed to the metal wall of a fluid container via a leak detection member, the leak detection member is approximately disk-shaped and has a penetrating diameter sufficient to allow the pipe to be fixed to the fluid container through the pipe. The through hole is surrounded by an annular protrusion with a height approximately equal to the thickness of the metal wall of the fluid container, and an annular groove is formed on the inner surface of the through hole and on the outside of the annular protrusion. The grooves communicate with each other through at least one passage, and the metal wall of the fluid container and the leak detection member are joined by seal welding between the inner surface of the former and the outer periphery of the annular protrusion of the latter. The outer surface of the former and the outer periphery of the latter are joined by seal welding, a leakage discharge pipe is led out from a groove on the outside of the annular protrusion, and the pipe is equipped with a leak detection means. Fluid leak detection mechanism for welded parts. (2) The detection mechanism according to claim 1, wherein a groove is provided on the back side of the annular groove on the inner surface of the pipe through hole of the leakage detection member to accommodate an O-ring. (3) The detection mechanism according to claim 1 or 2, which is applied to a tank for storing radioactive waste liquid or nuclear fuel.