ASME III ND compared to ASME VIII div 1

[LesT]

I am looking for a simple comparison of ASME III ND class 3 design requirements with that of ASME VII Div 1. What do I need to do extra for example to a simple pressure vessel designed accoprding to ASME VIII in order to comply with III ND?

 

[anooppillai]

hi,
Section III NC and ND are almost similar to section VIII div. 1, governed by design by rules. While designing based on sec. III NC or ND, wherever rules are not given you have to go for analysis(like the case with nozzle loads on the vessel). Loading of the equipment is classified into different sevice levels and u can take advantage of higher allowable stresses for extreme loadings probability of occurance of which will be much less than normal service levels. All the joints here are 100% radiographed. so joint efficiency is not specified.