L7M bolting over 2.1/2" diameter

[mombutto]

Hi all,

I wonder if someone could share with me if had experience with L7M (grade M) bolting over 2.1/2" in size with ASME VIII Div.1 code and stamped heat exchangers

The ASME II Part. D limits the allowable stresses to 2.1/2" although the ASME II Part.A for the SA 320 L7M bolting (table 1 - Mechanical requirements) states that this limit shall not intended as absolute limits beyond which bolting material could not be certified to the specification.
So, it seems to me that there would be the possibility to use L7M bolts eben with diameter over 2.1/2" inch, so admitted by the code also for stamped heat ngers.

I would appreciate if you could support me on this field.

thanks a lot to everybody in advance

 

[Cockroach]

What they are saying is that you need to test for those allowable stress limits and not extrapolate past the numbers listed in the table. This is the standard "scope of practice" statement that imply you, as the designer, are responsible to ensure fastener components comply to the code.

Which is why material testing specialists are in business. On the other hand, you could go to the maximum bolt diameter and put in more than required to hold you to the letter of the law under the code.

Either way, your choice.

Regards,
Cockroach