Allowable Stress Values for ASME Section II Part D 3

[RobsVette]

Hi Everyone,

This is probably a relatively simple question, but its one I do not know the answer to.

I am looking at performing design calculation using SA-395 which is a nodular cast iron and does have a section in section II part a. I cannot however track down allowable stress values to use from section II part D.

What do you use for allowable stress values in this case?

Thanks,
Rob

 

[SnTMan]

This usually means it is not a permitted material for the Code Section of interest (Sec I, Sec III, Sec VIII).

There are provisions, at least under Sec VIII, Div. 1, to use non-listed materials, but it is usually more practical to find a permitted material of a similar composition and product form.

And yes, Sec II, Part A contains specifications for numerous materials not permitted for boiler and PV work.

Regards,

Mike


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

 

[RobsVette]

SnTman,

Thanks for the quick response. Oddly enough, the vessel I am looking to verify a calculation for, actually exists already and is 10 years old. Its a 40" OD, 1.4" wall thickness vessel constructed of SA-395 according to the data report. It was built in 2013.

In absence of established values, I will default to the explanation in section II part D in mandatory appendix 1 and use the Tensile strength over 3.5 factor for determining the appropriate stress value.

Sorry for the lack of clarity.

Rob

 

[marty007]

This material oddly defines the allowable stresses directly in ASME VIII-1, look at Table UCD-23.

I don't get into part UCD very often, so don't know any other requirements... Take a good read through this section.

 

[RobsVette]

Hi Marty007,

Thanks for the tip. I found what I was looking for. I dont spend alot of time in that section of Section VIII and it didnt even occur to me to look there.

Thanks for the help,
Rob

 

[SnTMan]

marty007, thanks, good to know. I never deal w/ UCD myself either. OP did not specify Section of interest as well.

Regards,

Mike

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