Appendix 2 and B16.5 Flanges

[monk75]

Can standard 150# ASME B16.5 flanges be considered as complying to Appendix 2 flanges?

 

[reza100]

No, most of B16.5 flanges will fail if you do App 2 calc.

 

[david339933]

Try a search.....discussed umpteen times on this site.

 

[monk75]

Thanks for the quick response. Maybe you might be able to help further. Why does UW-21(d)state "When ASME B16.5 slip-on flanges are shown to meet all of the requirements provided in Appendix 2, weld sizes from Appendix 2 can be used? What requirements is UW-21(d) referring to? Seems to be conflicting??

 

[monk75]

I'm fairly new to this site as far as asking questions and have tried to search this. Maybe I'm not asking the correct question?

 

[SnTMan]

monk75, weld sizes for slip-on flanges required per UW-21 are larger than required per Apx 2. Compare UW-21(c), Fig UW-21 to Fig 2-4, Sketch (3) for example.

UW-21(d) provides a basis for using smaller welds.

As for your first question, if it complies with all of Apx 2 requirements, yes. Often they don't though.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[monk75]

Thank you for clarifying

 

[JStephen]

If the actual design pressure is low enough that the flange works per Appendix 2, then you can use that option and are able to use smaller welds, is how I interpret that. Which would mainly be larger flanges (24", 20", etc) where the hub thickness and corresponding weld are pretty substantial.

 

[monk75]

Thanks to all for your comments