combining ASME-laterals with EN pipes 2

[Prototyp]

I am currently planning a carbon steel pipe system with pipe dimensions (outer diameter, wall thickness) according to EN-standards. As there are no laterals with EN-dimensions available I am considering to buy laterals with ASME dimensions like shown in figure below and butt-weld them to the pipe.

Is this a good idea or do I have to expect any problems by doing so?

 

[XL83NL]

What’s your design code?
You have quite some hi-lo, giving about 8 mm difference in ID, roughly 4 mm on the wall. If you’re going to taper the ASME fitting, you might fail on the hoop stress equation. I’d make a transition piece to make sure the two fittings can be welded together without failing on the minimum required wall thickness, and to avoid any misreadings on the radiographic films in case the butt weld will be RT-ed.

The transition piece can be easily machined from a piece of bar.

 

[MJCronin]

"I am considering to buy laterals with ASME dimension"....... Really ?

Which ASME standard ?.... Certainly not B16.9 !!!!

Laterals are not pressure rated in the same way as piping elbows and tees constructed certified and tested in accordance with ASME Standard B16.9

I don't care what your low-price Chinese fabricator is telling you in their sales literature......Pressure certification must be done by a piping engineer and the fitting must be evaluated as a unique fabrication in accordance with the rules of ASME B31.1/B31.3

MJCronin
Sr. Process Engineer

 

[XL83NL]

Who says this is an ASME B31.1/31.3 design? Based on the info given, EN 13480 is more likely. EN 13480 has rules for laterals, whereas B31.3 currently only has a Code case for that.

 

[Prototyp]

EN 13480-3 is correct, but lateral fittings according to this standard don't seem to available. They have to be self made by the piping company. Additionally EN 13480-3 doesn't point out clearly how laterals should be calculated.

I need a lot of laterals for the requiered pipe system, operating temperature is between 15 and 35 °C, nominal pressure 16 bar.

If someone has a clue about this topic please help.

 

[Prototyp]

MJCronin, when I am talking about ASME- or EN-based I mean the dimensions, inner diameter and wall thickness.

 

[MJCronin]

Proto ....

When I am talking about dimensions and wall thickness I am saying that laterals are a unique component that must be individually designed by a competent individual.

When you talk about lateral dimensions "including wall thickness" realize that you are determining the pressure retaining capability of the lateral.

When you show me a sketch of a lateral showing dimensions that states "lateral in acc ASME Standard" I sense confusion or fraud.

When you purchase an ASME B16.9 elbow or tee, you are buying a component that IS AT LEAST AS STRONG AS THE PIPE ! This is why the B16.9 standard was written !!!...... if you are purchasing a lateral you do not get the same guarantee. You have to look to a different methodology.... Such as the area-replacement methodology contained in B31.1 or B31.3 ......

(No XL83NL, I am not saying that this must be a B31.1/B31.3 system. I am saying that the laterals cannot be purchased off the shelf based on the weak promises of a foreign supplier.

IMHO, there are some significant problems in this piping design process when the staff do not know which Codes and standards govern....

MJCronin
Sr. Process Engineer

 

[MJCronin]

https://www.eng-tips.com/viewthread.cfm?qid=235247

https://www.littlepeng.com/single-p...-Pressure-Design-of-Welded-Branch-Connections

MJCronin
Sr. Process Engineer

 

[Prototyp]

Thank you, I checked B31.3. The laterals I need can be butt-welded from the best available EN wall thickness pipes without needing reinforcement.

Nevertheless it might be more cost-effective to buy ready-made laterals which stability is even higher because of the bigger wall thickness.

 

[LittleInch]

Laterals and Wyes are subject to forces and stresses which are not straightforward.

Even someone like Bonney Forge only make stock forgings for laterals up to 2".

If you have a load then someone like BF will make you a bunch of them, probably milled out of solid bar.

5" is a strange size and is also quite big for these types of fittings without some sort of bespoke design.

I agree with the others above - this is not a standard ASME xx.xx fitting. MSS-SP-97 goes to 2" only for the welded fitting design.

B 31.3 design on branches is for pressure containment only. Other stresses and forces need to be allowed for separately.

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

 

[XL83NL]

EN 13480-3 2017 para 8.6 has rules for special piping components. Otherwise, refer to B31 code case 204.