Per B16.5, are 2-1/2" and smaller 900 & 1500# flanges equivalent?

[timsch]

Per B16.5, 2-1/2" and smaller 900 & 1500# flanges are dimensionally equivalent. Assuming that the same material spec is used for both of them, a calculation would result in the same pressure retaining capability.

Would a 2" 900# flange stamped ASME B16.5 still be limited to the pressure rating listed in the applicable table? It seems like a silly question to me, but I don't see clarification on this issue in B16.5.

One of our project managers had a thermowell manufactured using a 2" 900# flange when a 1500# flange was specified, and now we need to justify it to the customer. Running Appendix 2 calcs may result in a greater thickness than what B16.5 requires, so that's not my best option.

 

[SnTMan]

timsch, I'd say if you cannot justify it to the customer based on dimensional equivalence alone, calculations of any sort will do you no good. Although you might have a look at Annex B, B2.

Lesson in careful, detailed work for your PM.

Regards,

Mike


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

Afterthought: Maybe you should confirm the flange marking.

 

[timsch]

The customer is aware of the dimensional equivalence, but is not willing to take it any further than that. At this point, we're trying to get the MTR reissued with a dual-# rating.

I am not sure what Annex B, B2 are. Another thread on this forum, stated that this is METHOD USED FOR ESTABLISHING PRESSURE–TEMPERATURE RATINGS, which is Annex B in B16.5-2003, but which is now NONMANDATORY APPENDIX A in the -2013 edition. Is that what you are referring to?

Yes, the PM, who is a pretty conscientious person, won't forget this lesson soon.

 

[mk3223]

IMO, since the 2" flange is the same for both 900# and 1500#, the vendor may provide the proof to show the flange tested per 1500# rating if done in the shop.

 

[timsch]

If by vendor, you mean us as the manufacturer, the thermowells have already been delivered to the customer on a rush. Hydrotesting to a higher rating would have been a good resolution.

 

[SnTMan]

timsch, yes, I referred to -03 Edition.


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

 

[mk3223]

I hoped the manufacturer who made the 2"-900# flange might had the pressure test record of the 1500# rating. Because, it's hard to persuade the buyer without a real test data.

 

[SnTMan]

B16.5-03, 8.1, "Flanges are not required to be pressure tested."

Regards,

Mike

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

 

[timsch]

Thanks for all of the input. We did get the flange supplier to issue a revised MTR showing both 900 & 1500# ratings, which should satisfy the customer.

 

[KevinNZ]

If the dimensions and material certificate shows the flange meets the requirements of class 1500 then there is nothing else required. If for some reason someone thinks it does note meet class 1500 requirements then it will not meet class 900 either.