What is the minimum distance required between the opening and the circumferential weld of a pressure vessel?
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What is the minimum distance required between the opening and the circumferential weld of a pressure vessel? I saw it somewhere before, but I can’t remember now. Could someone give me some guidance? Thank you
It generally needs to be greater than 100 MM, but it’s okay if it’s not possible to reach the weld; what matters is that the expansion testing yields satisfactory results.
Reply to 2# 【Speechless】 Could you tell me which standard sets this rule? I know 100mm. Now it’s necessary to know the source
This post was last edited by qilupzh on 2011-5-19 10:53 regarding GB150 10.2.4.5. The spacing between the longitudinal welds of the pressure vessel head and shell shall be 3 times the plate thickness and not less than 100 mm. The minimum length of the circumferential ring section is 300 mm, and the minimum weld spacing is also 300 mm. According to GB150, if RT is within 1.5 times the radius of the opening, there is no distance restriction. Otherwise, opening within a radius range of 1.5 times is not permitted.
Reply to 3# KK123: It should be based on the tolerance specification or 150; I’m not quite sure anymore.
It turns out that both the code requirements and the guidelines for manufacturing and inspection under GB150 specify a minimum distance of 100; however, this is a recommendation rather than an absolute requirement. In practice, the openings can be made on the welds, but a 100% flaw detection must be carried out over a distance equal to 1.5 times the diameter of those openings, with the acceptance standards being the same as those for longitudinal seams.
I think it’s the maximum of 50mm and 3 times the plate thickness. This is the distance between the takeover point and Ring Peak! But there, I searched for information for ages yet still couldn’t find the source! !
Personally, I believe it is advisable to avoid overlaps in stress concentration areas, that is, to make holes outside the range of SQRT(R.δ) to 2.5SQRT(R.δ).
Greater than 1.5 times the opening diameter; otherwise, RT is performed on the welds covered by the projection.
Still follow ASME UW-14!