Dear colleagues,

I have a problem with understanding of PW-39 note 12 (d).

I have header DN 150 thickness 21.95mm, SA-106 B. The headher has 5 nozzles acc. to PW-16.1(z).

Nozzle 1-3: 38.1x4.57, SA-192
Nozzle 4-5: 48.3x5.08, SA-106 B.

Can someone explain to me what is the meaning:

"the connections are not placed in the vessel such as to form ligaments, the efficiency of which would affect the vessel thickness"?

I am not sure if I have to stres relieve or not.

Thank you for your potential answer.

Jiri Kroneisl

Jiri,

If you design your header using PG-52/PG-53 headers that means connection are forming the ligaments. If you design your onnections in accordance with PG-33 then it means connections are not forming the ligaments.
In former case, you cannot waive out PWHT reuirements under note 12.
Hope it helps.

_________________
Thanks & Regards,
Nasir
Welding Engineer
DESCON Engineering Limited.
Lahore, Pakistan.
Mobile # 0092-336-4145402

Dear Javed,

Thank you for your answer.

According to our design and calculation department this connection is forming the ligaments.

I will use stress relieveing.

Jiri