ASME U Stamped Pressure Vessel Assemble at Site

That requires an R stamp (for field repair.)

i'm not sure if we can consider it as repair job

Why you weld the equiepment? To cut after? The vessel is stamped "U" now?

the vessel is only fabricated in 2 section and to be weld back together at project site(not at manufacturer workshop). it's new and client also want U stamp...

No problem, is possible. Call you ASME agency/Inspector

Thanks 4 the info. Ciao

Sometimes the equipment cannot be delivery in one piece due to limit in transportation.

For example, let's say a column tower height 50meter but maximum limit for road transportation from sea port to the project site only permit 30meter.

So, the column have to cutted and shipped in 2 pieces. Then the two pieces shall be assembled at site including welding, NDE test, local PWHT and also hydrotest. It is not repair job eventhough the scope is almost the same.

It's a lot of work...sighhh...

Thus, just wondering if there is a rule in ASME that said these kind of procedure cannot be allowed. I've read also UG-120(c) and is it related to Partial data report?

It is a lot of work...

However, the vessel will have been fully completed, hydrotested and U-stamped in your shop. Once applied, it doesn't come off.

If you cut it apart for shipment, you'll need to repair it (put it back together). To do that you'll need someone with an R-stamp program. The R-stamp goes on in addition to the U-stamp.

Consider an alternative re-assembly technique, such as a shop-made bolted flange for which a weld repair is not needed. Once tested at the shop the unit then may only need a pressure test in front of the insurer's Engineer/Surveyor at site, though do check first during the design process; in any case the site inspection and testing will be simpler on a non-modified vessel.

I concur with the sage PWSlack.....

In the petrochemical and power industry, the more common solution is to utilize bolted, flanged joints ( commonly called "body flanges) in the design.

After all other alternatives have been considered, it is usually easier to ship a large flanged vessel to the site in multiple pieces.

Another benefit: Bolted joints also makes assembly easier than trying to make and align a huge welded joint.

Please respect those trying to help you.

Give us more details of the vessel's size, weight, orientation and place of assembly....

I have not seen that it is common to flange large pressure vessels. I have PWHTed many vessels that were welded however. I don't know what you consider large, but I think cat crackers, coke drums, vacuum towers. etc.

Sometimes the client will have a vessel that is too long to fit in his furnace, sometime there is not enough room in the plant to place a full length vessel, and sometimes it is shipping.

However I have seen 300 ft vessels moved by road.

300ft, that is really long but for this particular project, the regulations (YPFB) doesn't permit road transportation exceeding 30m....it's a challenge

hmmm...i never considered utilizing flanged connection, but i don't think it can be applied in my case because the column is about 2m in ID and 40m in height and the thk is about 4 inch. Weight about 200 ton. Also it has high D.T and D.P ; 220°C & 160 bar. And the fluid is very corrosive and toxic. (there is loose lining inside)

However, maybe it can be used as alternative solution and depending also agreement with the licensor.