Standard vs Nonstandard Vessels

[Doodler3D]

Hi,

I could not find a clear definition of standard/non-standard vessel in the code. Could someone elaborate on what classifies a vessel as non-standard? Is it a vessel that does not require ASME stamping or is an unfired pressure vessel similar to the definitions in EN13445? How is the design by analysis applied to a non-standard vessel?

Thank you.

 

[SnTMan]

I doubt you'll find any one definition. I'd say standard is a vessel of whatever use that you can buy from stock. Ex - air receivers, propane tanks, some heat exchangers, so forth. Non-standard - design and construct per buyer specifications. Either may be to Code or not and / or stamped or not.

Regards,

Mike

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

 

[Doodler3D]

Thank you SnTMan, I'll run with that but it is confusing.

 

[XL83NL]

SnT made a good remark. I think the answer lies in what you make the definition to be. Codes dont makes such definitions or distinction.
DBA for a non standard should be the same as for standard vessels, if you go by the definition SnT made.
There are a few exceptions. In the EU, there are various EN standards available for specific (pressure) vessels, or vessels for specific services. Like vessels for cryogenic applications, or air receivers.
Although not a design code, the SPVD is another way on how such differentiation is made.

Huub
- You never get what you expect, you only get what you inspect.

 

[r6155]

Fire extinguisher is a standard PV.

Regards

 

[Doodler3D]

@XL83NL

So my understanding is that whether a vessel qualifies as standard or non-standard depends solely on the application and not a pre-defined, specific geometric configuration.


Thank you, all.

 

[XL83NL]

It depends solely on how you define, I would say. To me, the application might make a difference; to another one, it might not.

Huub
- You never get what you expect, you only get what you inspect.

 

[IFRs]

I'd think a standard vessel was designed and built totally within the main body of whatever standard it was built to.

 

[Strook]

DoodlerDaru

Codes and Standards have been written to provide design guidelines for vessels. A simple way of udnerstanding it is that typical details such as cylindrical shells, flanges etc. are well understood. Testing and verification has been completed that allow code committees to develop these design guidelines, offering 'design by rule' provision. However, there are also many other details that aren't so standard, details that haven't been tested or verified. You might classify these as 'design by analysis'.

I was taught and teach others to design by rule wherever possible, and use FEA for vessels sparingly if at all. For this reason, a vessel that fits within the design by rule provisions might be categorised as "standard".

You may notice "standard" vessel types that are used in certain applications, such as fuel gas heater, re-boilers, air receivers etc. These should always be designed purpose- and application-specific to the project. In that sense, no vessel as a whole is "standard", as there will almost always be different design conditions (environmental, process, mechanical, HAZOP outcomes etc.)

 

[Doodler3D]

Thank you for your inputs IFRs, Strook.