parameter a2 of Figure UW-13.2 Sketch (r) and (s)

[Tridiartha]

Hello,

I would like to seek advices regarding the physical intrepretation of variable a2, as shown in ASME VIII Div 1, Figure UW-13.2 Sketch (r) and (s).

In those sketches, variable a2 is related with a construction line (with minimum 45 degree angle).

What is the purpose of this construction line?

Where could i find in the code, a relation between parameter a2 and ts?

I appreciate for any advices related with this matter.

Thank you.

Tridiartha

 

[SnTMan]

Tridiartha, first you need to thoroughly understand UW-13(e) and (f) rules for corner joints with flat heads, tubehseets, etc. UW-13(f) and sketches (r) & (s) provide alternate rules to UW-13(e) and related sketches and can produce a joint with perhaps less preparation and deposited weld than UW-13(e) joints.

You need to understand that use of UW-13(f) requires some knowledge of the ratio between the tensile strength in the in-plane and through thickness (Z) directions of the flat member of the joint (the K value). The less difference between the two, the less joint prep needed.

The detailed requirements are too complicated to go into just now, but to briefly answer your questions:

1) "What is the purpose of this construction line?" - The purpose is to more or less establish the weld penetration beyond the bevel (if any) required based on the assumed or known ratio between the tensile strengths, the K value.

2) "Where could i find in the code, a relation between parameter a2 and ts?" - It is found in the detailed requirements of UW-13(f), understanding that ts is first determined under the other relevant Code rules. a2 is then determined based on the details of the weld joint and other UW-13(f) rules.

Again I say, you need to first thoroughly understand UW-13(e) and (f) rules.

Regards,

Mike

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

 

[Tridiartha]

Hi Mike,

Thank you for the advice.

I have made a sketch to refine my question. Please refer to the attached sketch.

Is it correct to intrepret that point A (on that sketch) was the starting point of construction line?

Regards,
Tridiartha

 

[SnTMan]

Tridiartha, yes that looks right to me.

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

 

[r6155]

Do you believe that all the conditions stated in UW-13 (f) can be met during manufacturing and inspection?
Did you read SA-770?
Do you understand the K factor?
I suggest that you consult a welding engineer and a manufacturer.
I also suggest that you change the design.

Regards