Moratorium on Appendix 2 flange rigidity requirements 1

[michigander]

We are desiging a vessel with rather large body flanges that is a duplicate of a job done 10 years ago. ( I just love duplicates...) Now that the appendix S rigidity requirements have been included within App. 2, these new mandatory rigidity requirements are tripling the thicknesses of my flanges. I am aware of a code case that allows these rigidity requirements to be waived if there is service history with a particular flange design, but I have heard there is a code case that places an 18 month moratorium on the mandatory requirement of the rigidity calculations. Can anyone shed a little light on this.

Thanks!!!

 

[kooler42]

Code Case 2547

 

[rhg]

If the old large body flange ( 10 years ) is working without leakage, so the design is good. Just copy all dimensions of the old flange with the same material and no calculations is required.