Can butt welds with no pressure difference, whether inside or outside a pressure vessel, be classified as Class AB welds? [
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Can butt welds with no pressure difference, whether inside or outside a pressure vessel, be classified as Class AB welds? As the title suggests, I would appreciate everyone’s guidance
For example, since there is no pressure difference on the joint welds of the components, are they classified as Type A or Type B welds?
I just don’t understand what you mean by pressure difference
Welds of type ABCD are those in compressive members; the poster mentioned that components that are not under compression do not require classification.
It is not under pressure; it only serves to guide flow and direction, and is not a pressure weld.
Welds between non-compressed members do not need to be classified
I still don’t understand what the original poster meant; let’s use images instead to convey the message
What the original poster said about no pressure difference implies that it is a non-pressure-bearing component, while basically all the requirements in the standards apply to pressure-bearing components
GB150 specifies that only the weld joints in the main pressure-bearing parts of containers are classified into categories A, B, C, and D; welds that are not under pressure do not fall into any of these categories, and at most one category E weld may be present where it is connected to a pressure-bearing part
This post was last edited by letitbe on 2018-2-5 at 11:40. This issue can also be understood in this way: pressure difference refers to the difference in pressure inside and outside a container. When there is no pressure difference, the gauge pressure is 0. For equipment operating at atmospheric pressure, such equipment also has Class A and Class B classifications based on its longitudinal and circumferential welds. Moreover, the term “butt weld” mentioned in the question likely refers to the longitudinal and circumferential welds of equipment operating at atmospheric pressure