What type of welds are the welds between the heat exchange tubes and the tube sheet in 151? What is the basis?
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What type of welds are the welds between the heat exchange tubes and the tube sheet in 151? What is the basis? Thank you!
“For Class D welds, the heat exchanger tubes and the tube sheet are connected by fillet welds; according to the classification standards for Class D welds at 150 degrees, I consider them to be Class D welds.
Whether it is classified or not doesn’t have any practical significance; ordinary manufacturing plants are not classified as Category C. But theoretically, since it is a B and D combined weld, it can be classified as Category B according to high standards, while the lower requirements would apply to Category D. Now, many foreign manufacturers have strict requirements for non-destructive testing of these weld joints, requiring RT testing.
Generally, to ensure the welding quality of pipe ends, a hydrostatic test is conducted for those with a single tube sheet; for those with a double tube sheet, a pneumatic test is carried out on the liquid accumulation layer between the tube sheets, followed by a PT test.
I think it belongs to neither Category C nor Category D. Special consideration is required for its detection, which should be specified in the drawings.
This post was last edited by stronger0514 on 2010-3-16 at 19:43. It does not belong to any type of weld; GB150 does not provide any specifications regarding pipe ends, so it does not fall under any category of joint. One can define E on their own. Class F welds; some companies do it this way.
It seems to be a Class C weld. . . .
It belongs to Class D welds, in accordance with GB150 clause 10.1.6 d)