Graham Clayton
Mechanical
- Nov 12, 2020
- 3
I am trying to understand whether specially designed welded seals such as toroids can be exempt from fatigue analysis as per ASME nb-3227.7.
The deal meets the rules and therefore is exempt imo. However stress are saying that the seal itself is exempt but the weld is not. The way I see it is that asme has built in control with the addition of membrane stresses and bending stresses being less than 3sm and weld qualification requirements such that assessment of the welds is not required and also means no fatigue strength reduction factors are required.
Hopefully someone can shed light on this.
Thanks
Graham
The deal meets the rules and therefore is exempt imo. However stress are saying that the seal itself is exempt but the weld is not. The way I see it is that asme has built in control with the addition of membrane stresses and bending stresses being less than 3sm and weld qualification requirements such that assessment of the welds is not required and also means no fatigue strength reduction factors are required.
Hopefully someone can shed light on this.
Thanks
Graham
