The container opening is on the weld seam
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One of the pressure vessels we manufactured had openings on the welds due to an error in the calculation for material cutting – is this acceptable? Are there any regulations regarding this?
See http://bbs.hcbbs.com/viewthread.php?tid=419398&highlight=%BF%AA%BF%D7
The standard does not prohibit it; it is permissible. However, it is best to carry out post-weld heat treatment and 100% flaw detection in the surrounding area, ensuring full penetration
At the same time, communicate with the supervision and inspection team to reach a consensus, take appropriate measures, and it will be fine once approved by the person in charge
I agree with what was said on the third floor; in the future, we should try to avoid such issues when calculating the dimensions of the materials. It would be troublesome if the inspection department doesn’t approve it
The standard does not prohibit it, but some technical agreements do not allow it
It is generally not allowed; I agree with the opinion from the 4th floor.
May I ask where the information on post-weld heat treatment comes from?
Generally, you shouldn’t do this; it’s better to find a way to move it away
There is no rule that prohibits it, but generally it’s fine to have openings at the welds – no consultation is required. The key is to ensure that the diameter of the opening is 1… The diameter range of 5 times must undergo 100% flaw detection, with the acceptance standard being the same as that for the longitudinal seams of the cylinder.
I agree with the opinion above; we have had cases where openings were made on welds, but by performing 100% flaw detection using a diameter that is 1.5 times that of the opening, everything passed.
It’s possible. If the original longitudinal ring weld was subject to partial testing, then when performing reinforcement calculations, the weld coefficient should be 0.85; if 100% radiographic inspection is carried out, it doesn’t matter. According to ASME standards, this refers to Class A welds
It’s possible, but 100% flaw detection is required, and reinforcement might also be necessary
Let’s learn* a bit – what does the expert upstairs suggest? Please take a look at the GB150-98 standard. The standard specifies that various intersecting welds should be offset by 3 times the plate thickness, with this offset not being less than 100 mm. Don’t welds formed after making openings also fall under the category of welds obtained after welding? I agree with what was said above; according to our factory’s regulations, welds should be avoided as much as possible. If it’s truly impossible to avoid them, flaw detection is the remedial measure.
If it is not required by the contract or the user’s technical specifications, then it is permissible
The standard does not prohibit it; it allows it. It is sufficient to perform 100% flaw detection on the welds enclosed by a circle drawn with the center of the opening as the center and a radius equal to 1.5 times the diameter of the opening.
The relevant standards do not prohibit holes from being located on the weld. But try to avoid it; if it does occur on the weld, anyway. Testing can be carried out in accordance with 10.8.2.2 on page 128 of GB150.
It is generally not allowed, as stress changes can easily lead to accidents.
It is not allowed according to the regulations, especially for pressure vessels
There is no prohibition specified in the standards; the key is to conduct 100% flaw detection within a diameter range that is 1.5 times the diameter of the opening, with the center of the opening serving as the reference point. The acceptance criteria are the same as those for the longitudinal seams of the cylinder.