Difference Between PN and ANSI Rating

[eanlex71]

Dear All,

Can anyone enlightened me the other differences between PN and ASNSI rating apart from their pressure and temperature limitations.Example(PN40 to ANSI 300)

Regards,
EL

 

[Biggy]

They are dimensionally different.

Also ANSI is an imperial standard and BS4504 PNxx are metric.

A good source of flange tables is the RGB Stainless Ltd, Stainless Steel Products Manual. If you ask them nicely they will send you a free one!!

Biggy

 

[VenPipingEng]

As Biggy said: ANSI is an "imperial" Standard while "PNxx" is "metric" ... if you're trying to match an ANSI flange with a PN flange, you won't.

The common thing to do is asking the vendor (when you face a piece of machinery with "PN" flanges) to supply also the counter-flanges (as and additional ... yes, but this is less expensive that asking them to use an ANSI flange providing PN flanges is their standard)