Mandatory Appendix 28 1

[crca8515]

Hello, everybody.
I have a little problem understanding Mandatory Appendix 28, specifically 28-2(f)(2).
How exactly do I establish a₂?

I understand that angle theta shall be at least 45º, but it seems to me that there is no other reference to determine a₂.

Thank you in advance.

 

[SnTMan]

crca8515, see 28-2(a)(2). a2 is established by sectioning a welded sample to determine the line of fusion. Knowing a2, the other dimensions, etc can be established and calcultions done.

Regards,

Mike

 

[crca8515]

Mike (SnTMan),

Thank you for your quick answer.

Once I get a₂ from a welded sample,according to 28-2(f)(4), if a₂/t_s exceeds the value of K in the table, the requirements in (a) and (b) need not be satisfied.

So, I have to get the sample, check a₂ and, if compliant, I don't need the sample anymore?

Regards,

Carlos

 

[SnTMan]

crca8515, your first post relates to Fig 28.1(a), single bevel. Your second relates to Fig 28.1(b) double bevel.

But yes it appears that if a2/ts > K no further samples are needed. But also see 28-2(d) for establishment of K. For a double bevel detail.

Gotta tell you, I am not first hand familiar with the use of Apx 28. We had looked at the use of it in the past, decided for us UW-13 made more sense.

Regards,

Mike

 

[crca8515]

SnTman,

28-2(f) relates to double bevel: * Both members may be beveled as shown in Fig 28-1 sk. (b) *

I normally use UW-13, but for some thickness and bevel geometries, the a+b>=2t_s is not complied, thus I need to apply Apx 28.

Right now the next step is to do the sample and analyze it. If you're interested, I'll keep you updated on the subject.

Thank you for your support.

Regards,

Carlos

 

[SnTMan]

crca8515, yes please do, thanks