JPS63192587A - Method for testing weld zone airtightness - Google Patents

Abstract

PURPOSE:To reduce the cost of a product by forming an air duct on one hand of a base metal or a joining member to be butted in advance and carrying out an airtightness test of a welded zone via the air duct after welding. CONSTITUTION:The air duct 4 is worked in advance on a surface contact place between the base metal 1 and the joining member 2 which is to be the weld zone. Holes 5 and 5' for air pressure are bored at points A and B on the welded zone where the welding of the base metal 1 to the joining member 2 is finished and the air pressure is applied from the point A and the pressure is confirmed at the point B and an air leak of a weld bead part between the points A and B is inspected. Since the air duct 4 is formed in advance, the prescribed test pressure is loaded in a moment between the points A and B and the necessary time for the airtightness test is remarkably reduced. Further, since the necessary expenses for testing equipment is reduced, after all, the cost of the product is reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to tanker ship ballast tanks, side tanks,
This invention relates to a weld airtightness test method that is applied to airtightness tests of welds that require airtightness, such as steel plate joints in central tanks and welded structures of offshore structures and large tanks on land.

[Conventional technology]

As shown in Fig. 4, a conventional welding part is formed by forming a double-sided welding part 03 by touching the contact area between the welding base material 01 and the joining member 02, and then visually checking for defects in the welding part using a die check in an airtightness test. In addition, airtightness tests under pressure using fluids such as gas or water have been adopted.

[Problem that the invention seeks to solve]

The above-mentioned airtightness test method has problems such as leaving unknown parts of potential defects in the weld, requiring a large amount of testing equipment and test time, and in addition, it is difficult to detect the weld bead from both sides. A pair of small holes A and B are drilled inside the welded area covered with When checking for air leaks while applying soapy water or the like, the surface touching portions of the base material and the bonding member often come into close contact at a portion between the small holes A and B, making it difficult for air to pass through. Therefore, there is a problem that a long waiting time is required between applying air pressure to the small hole A and checking the air pressure at the small hole B, and the time required for the airtight test is wasted.

[Means to dismantle the problem]

In order to solve the above-mentioned problems, the present invention provides a groove to serve as an air passage in advance where the base metal and the joining member touch each other at the welding part, so that the groove intersects with the air passage at the surface touch at the weld bead surface. This test tests for leakage on the weld bead surface by applying air pressure inside the weld through a small hole. That is,
In a base material and a joining member where the welded part having airtightness is a full-circumference weld, an air passage is provided on either the surface of the base material or the joining member to be butted, and the air passage is subjected to an airtightness test. The present invention provides a welded part airtightness test method characterized by the following.

[Effect]

The welded part airtightness test method of the present invention is a test method as described above, so when applying air pressure to one small hole and checking the air pressure in the other small hole, even if the base material and the joining member are in close contact between them. Since an air passage is opened in advance in either the base material or the joining member, air can pass through easily, reducing the time it takes to reach a constant pressure, and eliminating the need for large-scale and powerful equipment. This is something that can be easily implemented.

〔Example〕

Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings. FIG. 1 is a perspective view of a T-shaped butt welded state used in a welded part airtightness test method according to an embodiment of the present invention and a conventional example. FIG. 2 is a cross-sectional view taken along the line ■--■ in FIG. 1 according to this embodiment.

FIG. 3 is a sectional view taken through points A and B in FIG. 1 according to this embodiment. The explanation is below. In Figure 1, 1
2 is a base material, 2 is a joining member, and 3 is a welding bead. A groove for an air passage is pre-processed where the base material 1 and the joining member 2, which will become the welding portion, come in surface contact. This groove is effective even if it is only a scar that is strongly scribed with a scribing needle, and it is sufficient to provide the groove on either the base material 1 or the collapsed joint member 2. The cross-sectional shape of the completed T-shaped full-circumference weld is shown in FIG. 2, in which an air passage 4 is provided on the joint member 2 side and welded to the base material 1. FIG. 3 shows a sectional view in which air pressure holes 5, 5' for air pressure are provided at points A and B shown in FIG. Next, to describe a usage example, a method to check whether the weld bead 3 can maintain complete airtightness when the joint member 2 is fully welded to the welding base material 1 is to apply air pressure to point A and check the pressure at point B. After that, spray soapy water etc. on the contact bead between points A and B to check for air leakage. At this time, the air pressure applied to point A instantly reaches point B through the air path 4. Therefore, since a constant air pressure can be applied instantaneously between points A and B, the airtightness test of the welded part between points A and B can be completed in a short period of time. After confirming that there is no leakage in the airtight portion, the air pressure holes 5 at points A and B are closed by welding, thereby completing the airtightness test. In reality, when the length between point A and B is 10 m, conventionally a waiting time of about 30 minutes was required, but by applying this method, the waiting time can be reduced to about 10 seconds.

〔Effect of the invention〕

As specifically explained above, in the present invention, by constructing the air passage before welding, it is possible to significantly shorten the time required to obtain the results of the weld seam airtightness test, and to reduce the time required for the test equipment. This makes it possible to reduce overhead costs and significantly lower product costs.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a T-shaped butt welded state used in a welded joint airtightness test method according to an embodiment of the present invention and a conventional example, and Fig. 2 is a cross section taken along the arrows in Fig. 1 according to the present embodiment. 3 is a cross-sectional view taken through points A and B in FIG. 1 according to the present embodiment, and FIG. 4 is a cross-sectional view taken along arrows 1--2 in FIG. 1 of the prior art. 1...Base metal, 2...Joining member, 3...Weld bead,
4... Air hole, 5... Air pressure hole.

Claims (1)

[Claims] In a base material and a joining member where the welded part having airtightness is a full-circumference weld, an air passage is provided on either the surface of the base material or the joining member to be butted, and the air passage is subjected to an airtightness test. A welded part airtightness test method characterized by: