B16.47 Flanges and the ASME Code

[innovation2]

I have a project that is requiring a 28" and a 36" 150# flange. I have determined that I will need a B16.47 Series A 150# flange since it incorporates MSS-SP44 specifications. I am trying to get the customer to use a slip on flange for the connections but as a worst case I will need to purchase a LJ flange. To get to my question, is it acceptable to take a slip on flange and bore it out for a lap joint connection. Will this negate it certification as a 150# flange. Will I have to provide calculation according to app. 2.

 

[doct9960]

jaybone,

B16.47 flanges are welding neck flanges. If you need slip-ons or LJ's for the sizes you mentioned, it will be a special design in accordance to ASME VIII-1, Appendix 2.

 

[innovation2]

That is what I was thinking. Thanks for the info. Anyone else have an opinion on the subject, I look forward to your responses.

 

[Shmulik]

jaybone,
Once you machine any part of B16.47 (or B16.5) flange – it is NO LONGER a "standard flange" under the definition of UG-44 , thus you are no longer allowed to refer flange's pressure-temperature ratings.
Now you are going to have a new flange, coincidentally have some dimensions similar to that flange describes by B16.47 – but you MUST recalculate it acc. to app. 2 requirements.

 

[innovation2]

That is what I thought. Thanks for your help guys.