Full penetration or fillet weld to heavy wall CS and SS

[jtseng123]

Dear all,
Is it necessary to use full penetration weld for welding support ring, beam seat, support clips of platform/ladder/pipe to vessel wall where thickness is greater than 50 mm ?
Any difference between CS and SS ?

This question is only for general service vessel, not for special service or high temperature.

 

No ideas and no suggestions, based mainly on lack of information.

However I do suggest you retain an experienced PV designer. It's not a specialty one should attempt to learn on their own.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[CodyK]

It all depends. An engineer can determine the required weld size based upon design conditions, sizes, and loads. I typically specified full pen welds with cover fillets for support clips, but it all depends.

 

An engineer can determine the required weld size

Including Microsoft engineers?

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[weldstan]

I have seen both fillet welds and full penetration welds of non prssure parts to heavy wall pressure parts of vessels per ASME VIII in carbon, low alloy and stainless steels. So the answer is, it's not necessary.

 

[CodyK]

Including Microsoft engineers?

That's exactly who I had in mind! Who else would it be?

 

[r6155]

Be careful with lifting lugs.

Regards

 

[jtseng123]

What exactly the issue if I only use fillet weld to weld this internal and external attachments to heavy wall?
SS will not be PWHT, but CS and low alloy yes. Is fillet weld prone to crack due to PWHT such that full penetration weld shall be specified ?
Like weldstan said I also have seen penetration or fillet weld used on heavy wall. I have a new project and I would not want to ask unnecessary or overkilled requirement to drive the cost high.

 

[r6155]

No problems with PWHT.
Nothing you need to specify, an reputable fabricator know when full penetration is required.

Regards

 

Any difference between CS and SS ?

Not very much, about 18% chromium and 8% nickel.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."