ASME Material and PMA

[IdanPV]

Hello all,

I am having a issue regarding the approval of ASME SA240-316L for PED using PMA(partial material appraisal).
As per the PMA, the values Re, Re,t, Rm, Rm,t shall be indicated.
Per PED 2014/68/EU, 7.1.1, Re for Austenitic steel is the 1.0% proof strength, and Re,t is the 1.0% proof strength at the design Temp.
Per PED 2014/68/EU, 7.1.2, The permissible general membrane stress, if the elongation after rapture exceeds 35% is the lesser of Re,t/1.2 and Rm,t/3 (Where Rm,t is the Tensile at the design Temp).

The NoBo(Notified Body) require to indicate the values of Re, Re,t, Rm, Rm,t and to satisfy the requirement of 7.1.2.

As far as I know, ASME II-D does not indicate the 1.0% values, and the Sy values of ASME II-D are the 0.2% values.
using the those values (from ASME II-D) will not satisfy 7.1.2.

Please advise.

 

[XL83NL]

Wow, that’s one heck of a tough nobo you got there. He’s going all the way even though it won’t matter - but he’s allowed to do that.

Ive had a similar issue in the past, but didn’t have to go that deep into the details. Also one might wonder how certain definitions in the PED in this matter need to be regarded. For example, how is the permissible general membrane stress defined?
In such cases as this, I challenge the nobo with an answer. Usually they’ll back off as they have no idea what they’re really asking anyway and don’t have the knowledge to really judge an answer.

What’s the design temperature for this case?
Where is your nobo located?

Huub
- You never get what you expect, you only get what you inspect.

 

[IdanPV]

XL83NL,

Thanks for you answer.

To be honest, it is not the NoBo, but the local representative.
Design temp. = 150°C, MDMT=0°C.

Any suggestion for an answer to made him back off?
I've already explained the differences between the Rp0.2 and Rp1.0 values, and explained that using ASME II-D values will not satisfy 7.1.2 and that the ASME values are Rp0.2.

Thanks again.

 

[XL83NL]

What's the difference between s local representative (representative of what), and the nobo, in your case? In your 1st post you mentioned NoBo.

Tell him 0.2 is less than 1. So, regarding that detail, you should be on the safe side with ASME.
IID lists yield and tensile and a function of temperature, afaik, so you can derive the stress allowable that satisfies ASME IID and PED.
At 150°C, the values are the same as for RT.

Huub
- You never get what you expect, you only get what you inspect.

 

[IdanPV]

The local representative is a worker of the NoBo. I'm not sure that the requirement to satisfy 7.1.2 came from the NoBo or it was just private whim of the local representative.
Anyway, he accept to stay with Rp0.2, and use the the allowable stress of Table 1A.

Thanks.