Pressure vessel nozzle made from plate 1

[men8th]

I have a supplier who is proposing to make the nozzles on a pressure vessel from thick plate, eg by boring the plate into a pipe shape. I can't find anything to specifically prohibit this in the code, but I don't think it's right because of the possibility of defects and segregation down the centreline of the plate. The appropriate product form is bar or pipe. Does anyone have any experience with this?

 

[SnTMan]

Or forging. Unbelievable, find another supplier.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

I have no experience with this because it is such a terrible idea.
Please tell me this isn't intended for (Nuclear).

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

 

[r6155]

Why not ASME VIII Div.1 Figure UG-40 (a-2)?

Regards

 

[men8th]

Thanks for your opinions all. Confirms my initial thoughts.

 

[JStephen]

See the flange requirements in 2-2(d).

 

[r6155]

JStephen- Do you mean that Figure UG-40(a-2) shall be treated as flange by Appendix 2-2(d)?

Regards

 

[r6155]

men8th, Can you tell us the diameter and thickness of the pipe?

Regards

 

[Ehiman1]

I don't understand why this could be a terrible idea....I have seen a lot of projects of pressure vessel in oil & gas field with nozzles from plate..for example SA-516 Gr. 70

 

[r6155]

extragol1A. Do you say , in example, plate 250 mm thick SA-516 70 cuted and machined to obtain a cylinder diam 114.3 mm (NPS 4) x 17.12 mm (XXS) x 250 mm long?

Regards

 

[SnTMan]

extragol1A, nozzles made from plate are usually roll & weld cylinders, not donuts cut from plate.

For this kind of detail it is possible that a lamination in the plate could extend completely thru the nozzle wall.

Plate donuts can be used for loose type Apx 2 flanges and I believe are permitted for studding outlets (Figure UG-40 (a-1 & a-2)) as well, but I'd personally most always specify forgings for these as well.

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[Ehiman1]

I was talking about nozzle up to 25 mm thickness..not 250 mm...probably we don't understand each other.
For thick plate usually I have designed self reinforced nozzles by forging and the final connection is made by pipe with standard NPS schedule...

 

[SnTMan]

extragol1A, refer to the original post...

The problem with sloppy work is that the supply FAR EXCEEDS the demand