ASME VIII Division 1 and 2 (Edition 2019) - Design Fatigue Curves and the new U-2(g)

[IdanPV]

Hello all,

I have two question regarding the new 2019 Edition of the ASME Section VIII Division 1 and 2.
1. I want to use Annex 3-F in order to determined the number of design cycles for SA-193 B7 bolt.
I guess the applicable formulas are (3-F.19) or (3-F.20) but I can't figure out which one I need to use since there is one undefined variable - SM (mark in yellow in the image below)

Where can I find the definition of this variable?

2. The new 2019 Edition U-2(g) stated that:

...Section VIII does not contain rules to cover all details of construction. Where complete details of construction are not given...

So when there are no rules for construction, the designer can use other methods, is it true?
The definition of "construction" as per ASME Section VIII.1 Foreword is:

Construction, as used in this Foreword, is an all-inclusive term comprising materials, design, fabrication, examination, inspection, testing, certification, and pressure relief.

But, when I look at U-2(g)(1) it refer to the Design nor Construction:

Where design rules do not exist in this Division...

And U-2(g)(2) is refer to anything but the Design.

The provisions of this paragraph shall not be used to justify the use of materials, joining processes (fabrication),
examination, inspection, testing, certification, and overpressure protection methods other than those allowed by this Division.

Which mean that the designer is not allowed to use U-2(g) to justify use of other construction method other than that who appear in the CODE

So, I am little confuse, in which cases a designer is allowed to use U-2(g)?

 

[TGS4]

S_M is S, the allowable stress.

I don’t understand your confusion in the second question. If there are rules in Division 1, you have to follow them. If there aren't rules, then you can apply U-2(g).

 

[IdanPV]

TGS4,

As for the second question.
Rules regarding the Design or the Construction?

At the first sentence of paragraph U-2(g) it says that:

"...Section VIII does not contain rules to cover all details of construction. Where complete details of construction are not given..."

Then, U-2(g)(1) is refer to the Design and U-2(g)(2) is refer to Construction.

I want to understand what exactly is "construction" as per ASME VIII.1? and why in 2017, U-2(g) were refer to the design and construction.

 

[TGS4]

Discuss with your AI, or submit an inquiry to ASME.

U-2(g) was given a complete overhaul that went through 70+ iterations. Don't compare previous versions to the current version. The two are essentially unrelated.