ASME Code Case applied to Material Requirement? (ASME boiler and pressure vessle code) 1

[Shockdesigner331]

Hello everyone. I hope someone can help me out.
I've got a customer drawing of a part that states in the notes:
1) Material, fabrication, and examination to be in accordance with ASME boiler and pressure vessel code section III division 1, subsection NF for a class 1 linear support.
2) material: alloy steel bar to ASTM A-434, 4340m class BD TO ASME CODE CASE N-249.

I have a copy of only section III, division 1, subsection NF of the B&PV code. I should be able to figure out how to interpret note 1 (fingers crossed). My question is regarding Note 2: First, where does one get the Code cases from? Second, how does this code case affect the material? It must affect the material, or certification requirements in some way otherwise why state this?

I really dislike this drawing. My belief is you should interpret, then put actual requirements in writing (dye pen, magnetic particle, test requirements, etc), and reference the portion of the spec it addresses if you have to show conformance. If you leave it up to a vendors interpretation then you could have non conformance, or a non conformance that doesn't show up until the part is made by a different vendor/interpretation.

Is it sufficient to give a material supplier a requirement for "alloy steel bar to ASTM A-434, 4340m class BD TO ASME CODE CASE N-249."?

Any assistance you could provide would be much appreciated.

 

[EdStainless]

You get the CC from ASME.
And yes many CCs do modify the material specification. I have seen them add tests, and change mechanical property requirements.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[metengr]

ASME Code Cases provide a means to allow material to be used under specific requirements or provisions to gain expierence in service. Code cases can be adopted into Code or withdrawn at any time. They have no affect on the material specification.

You do not specify a Code Case for ordering material. The Code Case is unique to ASME and applies only to B&PV design.

 

[XL83NL]

@ metengr; strictly, there are code cases as well for B31 codes, so not only B&PV, right?

 

[metengr]

XL83NL
Yes, indeed. I would not want to forget about the piping boys. They have their own set of rules.

 

[Shockdesigner331]

Thanks everyone.
So I understand that the Code Case has no impact on the material specification. BUT, if this code case has test requirements that the material must pass, for example if it states that tensile tests on the material shall show a strength above XX ksi. It would be an additional specification of sorts to apply to the material. Whoever is supplying the material would have to first start with the material per the material spec, then make sure that heat passes the additional specification of the Code Case. Or if it requires the material to be magnetic particle inspected, etc. So could this code case have a direct impact on the actual material used? after reading your responses I would think that is the case. Maybe I'm old school, but just passing the buck by pasting the spec you have to comply to is just asking for trouble.

If you work with this specification a lot, would you attach this code case to the material spec and have all of it as the material requirement?

I suppose that I would have to buy all the code cases, I couldn't get just the ones I need?

If this customers drawing is used again in say 20 years.... will the code case they mention exist? Will it be adopted into the spec? Will there be a good enough bread crumb trail to figure this out in the future?

 

[metengr]

Shockdesigner331;

If you work with this specification a lot, would you attach this code case to the material spec and have all of it as the material requirement?

You can or use excerpts to ensure supplemental testing is captured on the PO as part of procurement.

I suppose that I would have to buy all the code cases, I couldn't get just the ones I need?

Contact ASME.org.

If this customers drawing is used again in say 20 years.... will the code case they mention exist? Will it be adopted into the spec? Will there be a good enough bread crumb trail to figure this out in the future?

Maybe. It has worked for 100 years with ASME B&PV Code.


The way it normally works is this - a Code Case (CC) is issued for use of either a new material, Grade, Class or Type related to either a new or existing material specification (US or international) by the applicable Code book section.

When it comes to purchase of the material, reference to the applicable existing material specification or new material specification as stated on the CC and necessary supplemental testing requirements as stipulated in the CC must be on the PO or Purchase Specification.

Once the CC material is received, application of the Code Case by the ASME Certificate Holder is performed regarding use of specific allowable stress values, or temperature limitations for design.

Have you reviewed or seen a Code Case? They have the necessary information to procure material, which has to be available because it would have been used to generate the Code Case. At the end of the day, the Code Case number is referenced either on the item or in the data report for use.

As I mentioned CC's can either be adopted in the book section or annulled (deleted), because of lack of use or relevance.

 

[wsu1975]

Shockdesigner331 (Mechanical)
(OP)
Your statement “I have a copy of only section III, division 1, subsection NF of the B&PV code. I should be able to figure out how to interpret note 1…” is a problem. Do not forget that Subsection NCA also applies. There may be other subsections referenced as well that you may need as well.

The 1995 Code Case N-249-13, “Additional Materials for Subsection NF, Class 1, 2, 3, and MC Components Supports Fabricated Without Welding” provides the materials that may be used in addition to Table NF-2121(a)-1. This allows using ASTM A434 material with min yield, UTS and yield strength at temperature requirements in addition to the NF listed materials.

Finally, as you stated you only have only section III, division 1, subsection NF of the B&PV code? Are you kidding!!? I understand this may not be your decision to not have the tools needed. If you are doing code work, especially if you are doing commercial nuclear work, you better get the codes AND standards associated with it. For nuclear, you at least need ASME II, III, V, IX, XI to keep you out of code trouble. Applicable ASTM for non-SA materials also. There are options other that complete hard copies as there are electronic data bases with information.

Good Luck!
WSU1975

 

[Shockdesigner331]

Thanks Metengr, much appreciated.

wsu1975, I completely agree with you that IF I was designing components to this specification then I should have every piece of this specification. I totally, completely, 100% agree with you.

I originally stated that a customer drawing had these requirements on the part he wanted produced. I should have stated that this was a build to print. I should have also stated that this was my review of their drawings to see what kind of additional costs needed to be added based on additional requirements from the spec. My company doesn't usually do "build to print", we custom design and manufacture, so I'm very familiar to designing to aerospace specifications, and am fully aware of the work that goes into insuring all code requirements are met. What really irks me is what I consider an incomplete drawing done by an engineer who didn't feel the need to decipher the code and put the actual requirements the part needed on the drawing. Especially if I am going to outsource the creation of the part.

wsu1975, thanks for the example on Code Case N-249-13. This is kind of what I was thinking was the case. This code case could impose tighter controls on the material procured to ASTM A434. These additional controls would have to be flowed down to a material supplier. Thank you again.