Regarding the ASME code appendix 9 jacket design,

[ChiangJaron]

Dear expert,

Regarding the ASME code appendix 9 jacket design,
I had a question about the jacket type I and welding method fig. 9-5 (f-2),
Is it possible let the value "b" = 0 and increase a value and full penetration welding to make sure Y can be satisfied as code required.

Thank you

 

[Afox88]

I would say no. If you look at section 9-5(c)(5), under the description for 'Y=', I take the meaning of the last line to say that a and b must both be greater than the minimum of tc, ts or 1/4". Therefore, b must equal at least 1/4" unless your jacket is thinner.

 

[ChiangJaron]

Thanks Afox88.
I thought so, too.

It because the last line to say that a and b specification are additional requirement at 2013 ed. of ASME code,
before that, there is no any required on it.
It's very large effected to our fabrication sequence of jacket assembly at any job.