Nozzle Load Calculations 2

[SmallInfo]

Hi Experts,
Long time ago I found a pressure vessel spec (ASME SEC VIII DIV 1) online, where I found these nozzle loads, does anyone know which spec of unfired pressure vessel got this table of nozzle loads?
Thanks in advance!

 

[MJCronin]

"does anyone know which spec of unfired pressure vessel got this table of nozzle loads?"

None of them ...Not ASME VIII or EN or BS

You say that you found a "pressure vessel spec online.. Which PV codes or Standards were referenced in that specification ?

MJCronin
Sr. Process Engineer

 

[SmallInfo]

MJCronin,
Thanks for reply. My mistake, its section Viii dev 1

 

[Geoff13]

ASME Sect VIII has never had a table like this. None of the Codes I've worked with have a table like this.

I have seen some customer have tables like this to list what loads they want their vessel nozzles to be good for.

 

[Trestala]

Such tables are prepared typically by the Contractors or Client since actual piping design and loading will come much later than vessel fabrication.
Having that table allows the vessel designer to design the nozzle ahead of piping routing and flexibility analysis.
Piping designer will then have to adjust their design to not exceed that loading values on the tie-in with the vessel nozzle.

Each Contractor/Client have different values on that nozzle loading table depending on their experience and design basis.

 

[SnTMan]

Any clues given on the coordinate system?

Useless...

Regards

Mike

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

 

[SmallInfo]

Geoff13
Trestala
SnTMan
Thank you so much guys for your time and valuable comments. I got another table same to this but values varying a bit.

 

[Pavel_1976]

Look in DEP 31.22.00.31 for some allowable data for nozzle. Although API610 for pumps nozzles. But all of these are common practices of certain company.
Generally this values are really low in due to no one made detailed analysis of these nozzles. And there are some difference for which device this nozzle connected (for pump, heat exchanger and vessel).

And I have a question about combination (utilization) of several loads at the same time.
Sometimes really low allowable load means that if all applied loads are below any corresponded allowable value that means that design is accepted. But sometimes we should obtain common utilization factor (like Fx/Fxallow+Fy/Fyallow+Fz/Fzallow+Mx/Mxallow+My/Myallow+Mz/Mzallow<=1).
The API610 has more sophisticated rules for combination method.

Does anybody have a point of view for common practise of this approach? Because sometimes it is not clear in a vender documentation.

 

[RVAmeche]

I would agree that it's a table developed by a customer/client. You don't know the assumptions behind the table so it's not worth a lot other than a high level sanity check.

This article features a similar type table.

http://www.piping-engineering.com/nozzle-loads-part-1.html

Caesar II pipe stress software includes a set of nozzle loads taken from "Consideration of Nozzle Loads on Vessels in Process Plants", Ausgabe, 2007.

 

[Trestala]

@Pavel_1976, the DEP states those are acting simultaneously in the notes. For other Clients as well that is understood to be acting simultaneously and you can change it to the resultant value for nozzles on spheres or ellipsoidal heads.

API 660~663 as well provide nozzle loading tables, but those are sometimes overridden by the Client/Contractor specification.

Those tables were established before UG-44(b) was introduced and some nozzles would automatically have to increase flange rating just to pass with those table values for local stress and UG-44(b) on the flange.

 

[Cobra17]

API-660, Appendix 1 has loads.