L7M bolting over 2.1/2" diameter
L7M bolting over 2.1/2" diameter
(OP)
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
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





RE: L7M bolting over 2.1/2" diameter
(Hint: see this thread: thread725-341276: A320 Gr B8M Class 2)
Regards,
Mike
RE: L7M bolting over 2.1/2" diameter
I did not know double posting was nota good behaviour.
thanks for let me know.
RE: L7M bolting over 2.1/2" diameter
As to your original question, the problem becomes one of finding a supply(er) that can quarantee the properties in the larger diameters.
Most likely you will have to do the legwork to find it.
Regards,
Mike
RE: L7M bolting over 2.1/2" diameter
RE: L7M bolting over 2.1/2" diameter
thanks for your support.
I am investigationg through and asked to our AI and our qualified bolting suppliers.
It seems that, from the calculation and stamping point of view, the note A of SA 320 L7M bolting (table 1 - Mechanical requirements) gives reasons to allow it. About the material supply, our sub-suppliers said that they normally manufacture L7M bolting over 2.1/2" in size. That's important is to perform the heat treatment in the right way; the rest is done by the good quality of material now-a-days the mills supply.
It is funny tolearn that, the limit we kept for years in our design/manufacturing is not the same for our qualified suppliers. Life is strange sometimes!!
Thanks again
Mombutto