Interpretation of ASME VIII - Division 1, Para UW - 16e.

[Abdulwaheed]

Hi,

I am reviewing a vendor document for the design of a vessel. The vesse has a ManWay sized at 24" and I got a little bit confused.

ASME VIII - Division 1, Para UW - 16e says Necks and Tubes Up to and Including NPS 6 (DN150) Attached From One Side Only. Necks and tubes not exceeding NPS 6 (DN 150) may be attached from one side only on either the outside or inside surface of the vessel.

Does this Mean the 24" Nozzle must be welded both on the inside and outer surface of the vessel???

The Document provided only Nozzle Standout from Vessel Center Line with no information on where weld is attached and I have requested for this.

Thank you.

 

[gr2vessels]

Abdul,
You need to ask the welding details from the Vendor. I would have already received by now all the welding procedures for review and approval, including a weld map for code compliance (I'm assuming the vessel is custom designed to your specification). Did you approve the welding procedures before hand, before the manufacture commences? Normally, the answer to your questions was suppose to be in the approved WPS/PQR and welding map.
However, if you buy a standard vessel from a manufacturer line of products, those have pre approved certifications and all you need is a copy of that certification and the relevant manufacture quality certifications pertaining your product.

 

[Abdulwaheed]

Hi,

Thanks for you response. Your assumption is correct, vessel is custom designed.

I have asked and the Vendor would eventually send all the above named documents you mentioned.

However, I am still not clear on the Interpretation of UW-16(e).

"ASME VIII - Division 1, Para UW - 16e says Necks and Tubes Up to and Including NPS 6 (DN150) Attached From One Side Only. Necks and tubes not exceeding NPS 6 (DN 150) may be attached from one side only on either the outside or inside surface of the vessel."

Does this mean Necks and Tubes 8" and above must be attached (welded) from both sides of the vessel.

Looking forward to any response on this particular aspect.

Thank you.

 

[gr2vessels]

No, it does only refer to NPS 6 or smaller nozzles. However, you can weld a set-on manway one side only with backing strip as per FIG. UW-16.1 or similar other one side weld, depending on the approved welding procedures.

 

[Abdulwaheed]

Hi,

Thanks for your comments, fully appreciated.

I have been supplied with the WPS and Welding map with all the information I need being there.

Warm Regards