EN13445 Nozzles loads acc. to Clause 16 2

[FPPE]

Dears,

If we are designing a vessel according to EN 13445, is Clause 16 mandatory for the calculation of external loads on nozzles?
Thank you

 

[XL83NL]

The key is in part 3, para 5.3.2.4.1. Where it says if they are relevant.
That’s a different wording than for example UG-44. But it may end up the same, I think. Even if nozzle loads are not specified in the engineering design (for example by means of a datasheet), the PED still requires consideration of nozzle loads. The hazard and risk analysis will dictate the impact, but in my experience (not saying that’s how it should be), the manufacturer and nobo will only include them if they’re specified in the engineering design.

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

 

[FPPE]

Thank you very much for your answer!
I have not stated my doubt correctly, I meant if it is mandatory to use clause 16 (only when the design is EN13445), or if you can still design according to the code but using, for example, WRC107 for nozzle loads only.
Thank you

 

[EngineerEPC]

Kindly check Annex C in EN 13445 part 3. (Design by Analysis-method based on stress categories)
A) Some points taken from annex-C are listed below ===

Quote

1) It may be used:
— as an alternative to design-by-formula (see 5.4.1);

2) It may be used for a component or even a part of a component.

Unquote

B) Now excerpt from clause 5.4.1 ==

Quote =

In addition, two series of methods may be used to supplement or replace DBF:

a) methods based on design by analysis (DBA), namely Design by Analysis – Direct Route covered by
Annex B and Design by Analysis – Method based on Stress Categories, covered by Annex C;

Unquote
====

Clause 16 is Design by formulae (refer clause 5.4.2), So my interpretation is we can use WRC 107 alongwith Annex C of EN13445.
Please confirm with NOBO. Please let us know the final resolution.

Regards

 

[FPPE]

Hi Ariba01123, thank you for your answer!
I can't find the connection between "So my interpretation is we can use WRC 107 alongwith Annex C of EN13445." and the quoted points.

 

[EngineerEPC]

Hi FPPE,

Point B) mentioned in earlier post is for permission given by Code to replace Design by formula (i.e clause 16 in your case)
Point A) is same as B), just it is specified under annex C.

I request your attention to clause C.4.5.2 (Selection of methods for determining stresses) in Annex C (a para is reproduced below) ===
Quote

The choice of the method used for determining stresses is under the responsibility of the manufacturer. This
method may be numerical, analytical or possibly experimental.

Unquote

From above, i hope we can use WRC 107 alongwith annex C.
Please confirm with NOBO. Please let us know the final resolution.

Regards

 

[FPPE]

Thank you!
I have used WRC for EN13445 projects for over 300 equipments, and the NOBO has never had any complaints. My doubt comes from the fact that inspectors are often not really trained, so I wanted to get other designers' opinions on this.
I thank you again

 

[DriveMeNuts]

Nothing in EN 13445-3 is mandatory. It is just a collection of design methods.
It is the European Pressure Equipment Directive (PED) (2014/68/EU), which specifies mandatory requirements for CE marked equipment. EN 13445-3 is a harmonised standard which complies entirely with PED.
In the EU, you can design any vessel to any code or method, as long as that method complies with PED regulations. WRC 107 is essentially a stress categorisation method (developed from experiments), which complies with Appendix C of EN 13445-3, so it will therefore comply with PED. You will have to assess WRC 107 with the allowable stresses contained in Appendix C, because these allowable stresses are harmonised to PED.

 

[r6155]

I have worked with reputable companies that include external forces in the nozzles without any requirements from the users.

Regards

 

[r6155]

My doubt comes from the fact that inspectors are often not really trained, so I wanted to get other designers' opinions on this.

The design of external forces is not within the scope or work of inspectors. Can you clarify?.

Regards