pipe pressure class question

[LouisCho]

Hi

I have a question for pipe experts that you are here!

I have never worked with the metric pressure rating since today. I always used the standard US class 150, 300 and so on...Today I need to specifiy PN20 pipes. As I understand it's the metric equivalent of class 150. I always assumed that the PN was the nominal pressure in bar and the US Class rating was the nominal pressure in psi. If it,s the case, why it's PN20 and not PN10 as 150psi=10bars? In addition, class 300 = PN50!

How does it works?

Thanks

[dave]

Can someone chime in on this or is this not our department? Surely someone has an idea?

[Zortar]

Comparing DIN ratings to ANSI/ASME B16.5: PN20=150LB, PN50=300LB, PN68=400LB, PN100=600LB, PN150=900LB, PN250=1500LB, and PN420=2500LB. There are additional DIN PN ratings in between the ANSI/ASME ratings but from what I understand the ones listed above are the most common since they are interchangeable.