Inside radius limitaion in ASME VIII Div. 1

[birken]

Is there any limitations on inside radius of shell in ASME VIII Div. 1?
Can we design a vessel of 22 ft inside radius to ASME VIII Div. 1? If yes, what would be the construction /fabrication technique?

 

[fegenbush]

There is no explicit limitation on diameter. The vessel would have to be field erected which limits the number of contractors who would be willing to take such a job. Also, PWHT may be required based on the thickness.

 

[birken]

Thickness comes out be 20 inches. How would be the construction? Layered vessel?
Need to submit a reply to one client expecting us to do this job.

Birken

 

[SnTMan]

birken, some advice, if you can't do it, don't quote it.

Regards,

Mike

 

[fegenbush]

birken,

You have something serious with which to contend if the thickness is 20 in. I have that as 1,350 psi at 650°F (cylinder, SA-516-70) which is unusually high for a 44 ft diameter vessel.

Please provide the design parameters and perhaps more assistance could be given.

 

[birken]

SnTMan,
Won't be quoting but need to know how this query should be handled with proper reasoning from code.

fegenbush
Internal Dia. - 44 ft.
Length (TL/TL) - 160 ft.
Operating Pressure - 960 psig
Design Pressure - 1650 psig
Operating Temperature - 45.74 Deg. F
Design Temperature - 150 Deg. F
Material could be taken CS
If you need any further information please do let me know.

Birken

 

[SnTMan]

Not at all familiar, but I would think, yes, layered vessel. Any common features, nozzles, girth flanges, etc, etc?

Regards,

Mike

 

[sanshu1111]

Birken,
What is this vessel, for storage or a process vessel? Dont know if any pressure vessel plate material is available in appx 500 mm thickness as most the the ASME plate material specs are limiting thickness to approximately 150 - 200 mm range.

Fabrication and handling of single equipment appx 15000 ton????? May be few options to make it practical and economical;

1. Spherical vessel if only for storage purpose
2. Splitting into smaller vessels to keep minimum required thickness to a max upto 190-200 mm range (SA 516 Gr 70 limit is 205 mm)
3. Using high strength steel if allowed and economical

Regds

San

 

[birken]

San,
It is a sludge catcher and client is asking it to be a one piece.
Can we consider layered vessel construction?
Regrading handling and transportation, we already have the quote available to handle such weight and volume.

Birken

 

[fegenbush]

Layered construction is permissible under Section VIII Div 1, and that may be the most effective means of construction. That being said, I have seen it done, but it is not for the faint of heart. There are many things to consider in this design including the foundation. I have been told that for large sphere projects the cost of the foundation is on par with that of the vessel.

 

[sanshu1111]

Birken,
Dont have experience in construction of layered vessels so cant comment on fabrication for such a big layered vessel. Any design however is required to look into various aspects related to fabrication, handling, operation and maintenance as well.

Do you need a single slug catcher or two of similar size? If only one slug catcher is considered, it may be worth splitting into minimum 2 slug catchers which will help in case one slug catcher is down for some maintenance or inspection requirements.

Is it a firm requirement or budgetary estimate to evaluate various options? If space is not a constraint, may look into other configuration (eg finger type) and other design codes (B31.8/ 31.4) with high yield materials.

Regards

San