Pressure design for elbows to EN 10253-2

[XL83NL]

For a pipe class design to EN 15001 (or even EN 13480), Im having difficulties understandig the pressure design for elbows under internal pressure.


For straight pipe under internal pressure, EN 15001-1 prescribes the required wall thickness as a function of the pressure class (PN designation).
For pressure design of components (like tee's, elbows, reducers) under internal pressure, for elbows one can choose between type A or B.

It is not clear how one can readily determine the required wall thickness for type B elbows. I dont want type A elbows since they will lower my pressure rating (I try to get a flange limited pipe class).


More specifically, Im using 3D 90 degrees elbows acc P235GH. Anyone who has experience with this subject, willing to share share some insights?

Perhaps Im missing some simple point which may make it a whole lot easier, but after few days of reading and studying, cant say more than that the design formula's are like crazy (looks like Ill need MathCAD for solving them - not even sure if it can be done with Excel), not straight forward, en the euronorm itself is full of unclear phrases making it fyuzzy to get a good grip of what needs to be done.

 

[XL83NL]

Anyone who can share some insights?
Or is this one of those unused design standards no one's familiar with (caus the standard doesnt work)?

 

[LittleInch]

I had to go look it up to find it is low pressure gas pipe design. What I can't work out is why you need to calculate this - can't you just buy one at various pressure ratings? Are you using PE or steel or copper or stainless?

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[XL83NL]

The elbow material is EN 10253-2 P235GH.
The piping system is designed acc. to EN 15001-1.

AFAIK, you cant buy an elbow to a PN designation (e.g. a PN 16 elbow).

 

[XL83NL]

Anyone with thoughts/ideas?

 

[SverkerO]

Mayby not any help for you, just a reflection from my use of the EN 10253-2.
What we usually do is to just order the fittings as type B. Then per definition they have the same strength to inner pressure as a straight pipe with the same material and dimension - end of story (we just calculate the straight pipe)

Best regards
Sverker

 

[XL83NL]

Thanks for your shared experience SverkerO.

After some reading in EN 10253-2, Ive always been under the impression that for type B the reduction factor was required.
Now I see it isnt, it's just that the Code isn't clear in this. Strange I dint noticed it before.

Still find all these EN standard f**in* strange. Can you imagine weldolets are designed to EN 15001-1?