JPS628733B2 - - Google Patents

Description

[Detailed Description of the Invention] Conventionally, in water filling tests of storage tanks using seawater, when the test period is long, paint or corrosion inhibitors are added to the water in order to prevent corrosion on the inside of the storage tank. Corrosion prevention methods were sometimes adopted.

In water tests using seawater, the parts where particularly severe corrosion (pitting corrosion, etc.) is observed are the welded parts of the bottom plate and jig marks, where the period of contact with seawater is the longest and where earth and sand accumulates.

To date, there have been cases where other companies have applied anti-rust tape or applied oil to welds as a corrosion prevention method that targets only welds, but there are very few types of corrosion prevention methods. .

Painting is considered the most reliable corrosion prevention method, but it is difficult to apply to welded parts where magnetic particle inspection is performed after about a month of water testing, due to the increase in work items, lengthening of the process, and cost. It has the following.

In other words, if a vinyl coating or other paint has been applied, the vinyl coating must be removed before performing magnetic particle inspection of the welded area, which is required after the water test, but the welded area must be ground with a grinder. Even if it is attached, there are many unevenness and it is difficult to peel it off. It is the diameter of the storage tank
In cases where the weld line is 100 meters long, the length of the weld line is extremely long, making it difficult to remove the vinyl coat that has entered the recesses of the weld and did not peel off with a brush.

In addition, when using corrosion inhibitors, they must be added in large quantities in order to fully demonstrate their anticorrosive effects, making them difficult to use due to cost considerations, and sometimes requiring water quality treatment when draining water. This is to be expected.

Next, how to apply rust-proof tape is that rust-proof tape is relatively hard and cannot be applied directly to a 100m long welding line without wrinkles. can get inside.

The present invention was devised in view of these drawbacks, and its purpose is to solve the drawbacks of relatively hard anticorrosion tapes and the drawbacks of vinyl coatings, which are difficult to peel off from welded areas with many irregularities, by a combination of the two, and to provide double-sided tapes. To provide a corrosion protection method for a welded part on the inner surface of a storage tank during a water-filled test, which can improve adhesion by interposing a tape and make the welded part completely waterproof during a water-filled test.

That is, since anti-rust tape is relatively hard, it is impossible to attach it along a long weld line without wrinkles, and if wrinkles form, water will seep through the wrinkles during a water test and the weld will rust. Also, although vinyl coating is completely waterproof, the welded area is very uneven even if treated with a grinder, and when the vinyl coating is removed, even if the steel plate part is completely peeled off, the vinyl coating remaining in the recesses of the welded area can be removed with a brush. The welded parts of a storage tank with a diameter of 100 meters must be removed with a similar tool, but it is a difficult task to remove the welds.

Therefore, in this application, we avoid applying vinyl coating directly to the welded part using anti-rust tape, and cover the edges and wrinkles of the anti-rust tape with double-sided tape to prevent water from entering and to prevent the adhesive from adhering to the vinyl coating. The vinyl coating makes it completely waterproof, and the vinyl coating can be easily removed without leaving any residue by removing the vinyl coating along with the anti-rust tape after the water test. It is.

In the present invention, before starting a water filling test, an anti-corrosive tape is applied to the welded part on the inner surface of the storage tank so as to cover the welded part, and a double-sided tape is polymerized and applied over the anti-corrosive tape and the steel plate, and then A vinyl coating is applied to the area that sufficiently covers the anti-corrosion tape and double-sided tape to insulate the weld from water and prevent corrosion of the weld during the water test, thereby maintaining a healthy weld. This relates to a corrosion protection method for the internal welded part of a storage tank.

To explain an example of shielding the welded part from water in this application, before starting the water filling test,
The welded part 1 is cleaned and a rust-proofing tape 2 is pasted as shown in FIG. As shown in FIG. 3, a double-sided tape 4 is pasted around the anti-rust tape 2 and the steel plate 3, and after the pasting of the double-sided tape 4 is completed, as shown in FIG. Vinyl coating 5 is applied to the area that sufficiently covers 4.

At the part where the welded part intersects in a T-shape, as shown in Fig.
After applying double-sided tape 4, vinyl coating 5 is applied.

Since the present application is constructed as described above, it is superior in terms of work process and cost compared to conventional corrosion prevention methods such as painting or adding corrosion inhibitors. Since it has a sufficient anticorrosion effect, the present invention has great industrial value in today's world where higher quality is required.

As mentioned above, this application deals with the welded part on the inner surface of the storage tank.
Before starting the water test, apply anti-rust tape to cover the welded area, apply double-sided tape over the anti-rust tape and the steel plate, and then apply the anti-rust tape and double-sided tape to cover the area sufficiently. It is characterized by a vinyl coating that isolates the welded area from water and prevents corrosion of the welded area during water tests.The area around the rust-proof tape, which tends to wrinkle, is completely covered with double-sided tape to eliminate gaps. At the same time, the vinyl coating completely isolates the weld from water, and for inspection after a water test, the vinyl coating can be completely and easily removed from the weld by simply pulling the double-sided tape, eliminating wrinkles and gaps. The vinyl coating compensates for the disadvantages of rust-proof tape, which tends to cause rust, and the waterproof tape makes it easy to remove the disadvantages of the vinyl coating, making it completely waterproof through the combination of the three.
Moreover, it is easy to work, can be done at low cost, and has the characteristics of having a sufficient anticorrosion effect during a water test.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the welded area with anti-rust tape pasted, Figure 2 is a perspective view of the rust-proof tape and then double-sided tape pasted, Figure 3 is the rust-proof tape and double-sided tape. FIG. 4 is a perspective view of the T-shaped cross welded area with anti-rust tape, double-sided tape and vinyl coating applied.

Claims (1)

[Claims] 1 Before starting the water filling test, apply anti-rust tape to the welded part on the inner surface of the storage tank so as to cover the welded part, apply double-sided tape over the anti-rust tape and the steel plate, and then apply anti-rust tape. A corrosion prevention method for welds on the inner surface of a storage tank during a water test, characterized by applying vinyl coating to an area that sufficiently covers the tape and double-sided tape, shielding the weld from water, and preventing corrosion of the weld during a water test. .