Hi forum, i need an assistance for 1

[AchillesC]

Hi forum, i need an assistance for reading elbow din dimensions sheet.
Example: if DN15 exist with 1,6 2,0 3,2 and 0,4 wall thickness, what is the right Radius for each: 17,5 28,0 or 42,5??

Thanks

 

[1503-44]

ID = OD - 2 x wall thickness
R = ID/2

 

[LittleInch]

You need to tell us what code or spec this is as I don't recognise what type 2,3 or 5 is though it looks like radius multiplier 2D, 3D, 5D.

Is this some sort of PE or GRE? Or stainless tubing or something?

But the wall thickness is the same for each series.

Not sure also what a "Maximum Pressure Factor" is.

Please enlighten us.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

The problem is that he did not say what radius he wanted to find, but all the wall thicknesses he talked about only affect internal radius, so that's what I gave him.

 

[EdStainless]

The elbow radius is what he listed from column "r".
It only depends on Type and not the wall thickness.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[1503-44]

Didn't see that.
If only we knew which type.

 

[HTURKAK]

The subject bend dimensions and notation is DIN 2605-2 ..

I preferred to paste the following picture ,excerpt from the same IMO, self explanatory ...

If nominal dia. DN 15 , and if type 5 , (r ≅ 2.5da ) , r=42.5 mm and so...

 

[LittleInch]

HTURKAT

Well done - I've never seen a fittings spec which had different elbow Radii.

Any idea what "maximum pressure factor" means (In English).

Typical Germans making it complicated in terms of type vs bend radius, so type 5 is actually 2.5D. Why????

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[HTURKAK]

I think this manufacturer could not comply with the requirements of the standard so , limits the pressure with a factor..

I would like the outline the DESIGN ASSUMPTIONS of the standard item 6,

( The wall thicknesses ( si and sa ) of elbows and bends are so selected that , they withstand the same internal pressure with the connecting pipes ....bends and elbows are with identical material , identical outer diameter ....)

The following is excerpt from the DIN 2605 and self explanatory..

Yes... if you say type 10 , ( Bauart 10 ) , the radius of the bend is 5*da ( da= external dia.) so, eventually type no. stands for inernal dia. of the bend or 2*r ...

 

[LittleInch]

Bloody hell this is getting complicated.

You have a type version (aka bend radius) 2, 3 or 5, you have a mysterious series 1-5, and now you have different thicknesses for the intrados and extrados of the bend! which presumably has to change gradually from one to the other as you go around the fitting

No wonder the vendor at the top has just used one wall thickness and then de graded the pressure. Or has he? the s value is the same as in your table so why the pressure reduction?

Too complex for me and I doubt anyone would stock all these different options.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[XL83NL]

The former DIN 2605 has (iirc) been incorporated into the current EN 10253-4, or more general, EN 10253 series for butt weld fittings such as elbows and tees.
It deals with a.o. type A and B fittings, which have a different background and need to back calculated by hand to determine its actual pressure rating. B16.9 is far more easy, and these kind of standards are one of the reasons why EN13480 is such a difficult code to work with.
My American friends, don’t be jealous on the European piping designer who has to establish a pipe spec line class with these EN standards. It’s a horrible pain in the &€s, esp. when one has to go to say pressures PN40 and above. I can tell from experience this is not an easy task. We’ve had situation where a simple DN40 316/1.4401 tee was made from bar and had 13 mm wall thickness instead of the required 3.2mm., simply because no European mill or stockist had the fitting we required.
Easiest workaround there is, is to use B16.9 fittings and write a PMA when compliance with the ESRs of the PED is required.

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