EN 13445-3 9.4.5.2 Problem with reinforced opening with nozzle

[none7]

First of all, sorry for my english.

I have a little problem with understanding one of the point in standard 13445-3.

there is a condition "shell reinforced opening without a nozzle shall satisfy the following condition d/(2*ris) <=0.5"

d is opening diameter
ris is shell inside radius

but when i want to use reinforced pad with nozzle, then shall I use inside diameter of nozzle as d or external diameter of nozzle as d?

than you for the answer

 

[MGZmechanical]

I think that when you have a nozzle you should apply 9.4.5.4 dib/(2ris)<=1 with dib =internal diameter of nozzle

Best regards

 

[none7]

you may have right but there is something bothering me.

i have nozzle reinforced by pad. i have VVD also and it check d/(2*ris) <=0.5.

strange is when i calculate in VVD nozzle without pad it checks dib/(2ris)<=1.

i'm now preparing calculation sheet in mathcad and i dont know how to bite this issue

 

[r6155]

It means that use of reinforcing pad is penalized.

Regards
r6155

 

[none7]

thank you for the answer

r6155: according to you, the condition with the pad must be checked. But for d shall I use diameter of the opening or inside diameter of the nozzle?

example: shell 168,3x5,6 / nozzle 88,9x8.
- without pad condition dib/(2ris)<=1 met
- with pad and d as dib with my corrosion and allowances condition d/(2*ris) <=0.5 met
- with pad etc but d as opening in shell condition is not met.

 

[r6155]

When a opening is with nozzle use “dib” (not “d” ), with or without pad . See figure 9.4-7 to 9.4-10

“d” = Diameter (or maximum width) of an opening on shell without nozzle

Regards
r6155

 

[none7]

in that case - VVD check is wrong.

9.4.5.2 says that if reinforcing plate is used (with or without nozzle) equation d/(2*ris) <=0.5 shall be satisfied. so form me with nozzle and pad the equation will be dib/(2*ris) <=0.5

Thank you for your time.