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How to convert PN number to ASMI/ANSI Class

Posted: 16 Oct 2010, 06:42
by saleemsahar
Will any body write how to find the equivelant ANSI/ASMI class for PN numbers of the valve?

2" PN 25 THRD-FPT Globe Valve bronze will be equal to?

Re: How to convert PN number to ASMI/ANSI Class

Posted: 16 Oct 2010, 10:34
by ben
PN is a french abbreviation for nominal pressure.
Normally, 20 PN is equivalent to 150 class rating in ANSI/ASME and so on...
50 - 300
68 - 400
100 - 600
150 - 900
250 - 1500

Basically, PN is the representation of approximate pressure rating in bars.

Re: How to convert PN number to ASMI/ANSI Class

Posted: 17 Oct 2010, 10:29
by saleemsahar
My question is still unanswered.I found also these information in one Mechanical Handbook.But the valve which we have to replace in forthcoming refinery shutdown,it is of PN 25.Your list does not include PN25.Also I need some refrence/documentry proof,source of information and its aunthenticity

Re: How to convert PN number to ASMI/ANSI Class

Posted: 17 Oct 2010, 10:44
by mechcolor
See the attachment.
It would not only provide you the right information regarding PN 25 rating as per ANSI but a documentary evidence also.
Hope this helps.

Re: How to convert PN number to ASMI/ANSI Class

Posted: 19 Oct 2010, 16:02
by alzuhd
Dear saleemsahar

there is no direct relationship between the metric DIN and EN standards from geometrical point of view.
This is imperative to know, then when you want to select a flange rating you will have to determine Maximum Design pressure and associated temperature, then u resort to the standard called for by client or jurisdiction as the case may be from which u follow a step by step procedure that will eventually lead u to the suitable flange rating
an example is ASME B.16.5

u will see as you proceed that other factors come into picture related to material of the flange
this will normally depend on the service conditions

the KSB page is misleading ...it is only their range of products and not geometrical equivalence...u can not mix standards

Re: How to convert PN number to ASMI/ANSI Class

Posted: 29 Oct 2010, 04:43
by farrukhawan
I totally agree with AlZuhd

Re: How to convert PN number to ASMI/ANSI Class

Posted: 30 Oct 2010, 05:17
by saleemsahar
Am sorry, I tried my best to understand this KSB table,but am afraid I did never learnt German...

Any ways we were able to contact OEM and PN25 valve will be in our ware house in few days