Hello, patch 4 was installed incorrectly. The weld was less than 150 mm from the casing so it had to be a stone type. Patch 2 covered one corrosion and now had to cover another nearby one. Since the distance to the welds could not be met, it had to be removed and made larger. They had to be...
Hello HTURKAK, I already know what the code says. But I want to understand why?
I think that in the case of very localized corrosion in the lower part of the bottom, it is better to install a large patch, even if it does not comply with API 653, than to install those 4 patches that do comply...
Hello, I work for a client who wants to comply with part 9 of API 653 to repair a bottom that has corrosion on the bottom.
In principle we had considered installing a May 24" patch, but API 653 does not allow it in the critical zone. So we have had to divide it into 4 patches so that it can...
Hello, my English is not very good, I hope you understand what I mean.
In my opinion it does not necessarily have to be centered. (example) If t2 is displaced above the corrosion area you can make one measurement above t2 and three below t2.
If the corrosion area is greater than 1000 mm then it...
Hello Creed2023,
Table 4.5 of API 653 is for products with a density less than 1.
For density greater than or equal to 1 you must take into account paragraph 4.4.6.3.
In your case according to table 4.5 (density less than 1) for a stress <27000 and thickness of the first course <0.75". The...
Colleagues, I wanted to tell you how you evaluate the casing of a tank according to API 653. We have some differences of opinions.
To evaluate a corroded area, we determine the current thickness as stated in paragraph 4.3.2 of API 653.
We calculate the minimum allowable thickness (tmin) as...
Hi HTURKAK, thank you for you answer
but in the paragraph it is confusing.
It says: welds or joints
It does not specify butt welds only.
I want to know if I can use E=1 for corrosion detected near the bottom-shell joint weld.
Corrosion is located less than 25 mm (1") from the bottom-shell weld...
The definition of E in API 653 refers to the following:
E is the original joint efficiency for the tank. Use Table 4.2 if original E is unknown. E = 1.0 when evaluating the retirement thickness in a corroded plate, when away from welds or joints by at least the greater of 25 mm or twice the...
We have a tank that has a strip of corrosion around the perimeter of the first course.
The corrosion stripe is produced by corrosion under insulation (CUI).
The corrosion strip has a height of approximately 100 mm and is located at the bottom of the first course.
My question is how to...
Hello, but what does the entire paragraph refer to?
to the area of the lower sheet that is covered by the patch? or only to the area of the lower plate where the inner bottom-shell weld is located?
Best regards
Hello, I have a question about the interpretation of paragraph 9.11.1.2.2 of API 653 on repairs in the critical zone.
What exactly does at the toe of the internal shell-to-bottom refer to?
I attach the paragraph:
9.11.1.2.2 A welded-on patch plate shall not be used if the covered bottom...
Hi, I have a query on API 653.
If I am currently inspecting a tank built to API-650, which edition of API-653 should I use for inspection and repair?
Should I use the latest edition of API-653?
Regards
