LPG sphere - plate support 1

[israeljrr]

Hi,

I would like to know if it's possible weld a pipe support over a plate that is welded/attached an sphere, without lose the ASME stamp?

Attached, you will find a sketch about the question previous.

Thanks in advance

 

[stanweld]

You may do so.

 

[gr2vessels]

You may not do so.
Your post and drawing are contradicting each other, but the end is that you may not weld the pipe support to the plate without properly re-engineering the sphere design.
On the drawing you point to the plate you intend to attach to the vessel, in the post you mention the pipe support you intend to attach to the plate. Either way, if you weld the plate to the vessel, you violate the code. If you add a pipe support to the plate, you also increase the external loads on the shell, so you must re-engineer the design.
Otherwise, you loose the U-stamp.
Cheers,
gr2vessels

 

[israeljrr]

Thanks gr2vessels, and yes I made a mistake in the drawing, because I've tried to show that we are going to weld the pipe support to the plate.
Aditionally, we will send the loads in these points for the sphere manufacturer, in order to be considered in the design of the shell.
Under these circumstances we will lose the U-stamp?

 

[SnTMan]

Is this new work or existing?

Regards,

Mike

 

[israeljrr]

It's a new work.

Regards,

Israel

 

[SnTMan]

israeljrr, if it has left the fabricator, then I think any alteration will have to be done under (if in US) NBIC rather than ASME.

Regards,

Mike

 

[Duwe6]

Depending on the erector - assuming site erection like most spheres - it can be Altered under the U-stamp. ASME only has to give way to NBIC after the vessel has been wet with product. Up until then, it is still 'new' and under the U-stamp.

 

[stanweld]

Assuming this is a new vessel, which is being field erected, the pipe support welded to a reinforcing pad welded to the shell may be done. Calculations must be supplied to support the design. The Manufacturer/Contractor shall be responsible for the Code design.

If this is an addition to an existing U-Stamped vessel, it still may be done and can be considered a Repair or Alteration dependent on whether it satisfies either 3.3.3 b) 4) or 3.4.3 of Part 3 of the NBIC. In either event, calculations will no doubt be required for AI review. If an Alteration, calculations must be done by a Holder of an R-Certificate.