PN numbers vs. valve class in asme standard

Dear moheshams,

Reply to your inqueries:

1. I will be so grateful if you give me the reference of the table.

The reference is Flanges - Ratings in Classes and Pressure Numbers (PN)

2. If I find a valve in which written for example ASME class 300 and this valve is butt weld type could I apply your table to choose another valve by PN and equivalent DN?

Yes. (Note: PN = Pressure Number = equivalent to class or rating, where DN denotes to NPS).

3. If you can introduce a reference to study about this subject I will thank you.

Sure, but I have ASME codes only, and ASME B16.5 for flanges and flanged fittings is a good reference to find the flanges dimensions and pressure-temp. ratings.

The references given are not correct. Galala gives a reference to Engineering Tool Box, which is not the source. For a start PN does not mean Pressure Number, as shown in Engineering Tool Box. PN originated in French & stands for Pression Nominale, which, when translated into English is Nominal Pressure. The original source is ISO 7268. You can also refer to API 6D, which gives you the English Translation of PN & also compares it to ANSI Class.

Vic

God answer as always Abdel.

milo

Thank you Milo.

DEAR SIR,

THE TABLE GIVEN BY YOU IS ABSOLUTLY CORRECT. I FOUND THESE EQUIVALANT PN TO ASME CLASS ARE GIVEN/USED IN CANDIAN STANDARD 'CSA'AND FFRENCH STANDARD 'NFE'. AS THEY HAVE ADOPED ASME CLASS FLANGES IN THERE STANDARD. NARMALLY PN ARE10,16,25,40,63,100,160 AND SO ON.GIVEN IN DIN AND EN STANDARD. NOW FOR ALL EUROP FLANGE STANDARD IS ' EN 1092-1:2007'.

THANK YOU.

V.D.DEODHAR.

Plz tell us wht is the meaning of PN 1 or PN 1.6 ??

Plz tell us wht is the meaning of PN 1 or PN 1.6 ??

PN(pressure number) 20=ANSI 150

PN50=300 #ANSI,PN68=400#ANSI,PN100=600# ANSI,PN150=900#,PN250=1500# ANSIand PN 420=2500 ANSI

What is PN40 equivalent to?

class 200

What is the ASME class Equivalent for PN 10 & PN 16

The Table starts from PN 20...

so how did they arrive with the comparison?

why is there a PN68, why not PN75? how about PN200?

and does it mean a PN10 and PN16 equivalent is ANSI 150?

Just to help out PN (pressure nominal) and DN (diameter nominal) are for metric flanges and valves

Where as imperial 6"150, 6" is the pipe size and 150 is the pressure rating in PSI

You would be lookin at a 300 rated valve

Where as imperial 6"150, 6" is the pipe size and 150 is the pressure rating in PSI

• 6" : is called Nominal Pipe Size not "pipe size"

• 150 : is a pressure rating, or pressure class, or rating or class, or 150#, but in no way to be followed by PSI, because it is not means a pressure, where it is a pressure-temperature rating.

dear all, this is the first time for me here... very useful information. I am now handling a pipe work to install a flowmeter that got 2 built-in DN flanges rating of PN10 but what's available in the market here are all ANSI.... question is .. will DN and ANSI flanges match and can be bolted together?... if so ..what's the equivalent or the chart for that... sizes of existing pipelines varies between 12'' to 30''. I need to buy flanges...so , i have to prove it technically that flowmeter with the built-in DN PN10 flanges can match and bolted with an equivalent ANSI FLANGES before buying any material. Engr. Zakarya

DN is differ than DIN.

DN is just size of flange or fitting, where DIN is a German standard other than American standards ASME.

For more details about relation between DN and NPS, see ASME B16.11, Para. 3 SIZE AND TYPE:

NPS, followed by a dimensionless number, is the designatio for nominal fitting size. NPS is related to the reference nominal diameter, DN, used in international standards. The relationship is typically as follows:

.....

Note: From NPS 4" and more, the relation between DN & NPS is: DN = 25 NPS

thanks for the reply. what i meant is the DIN... i have no thread in this piping job... it is all flanges to be welded in pipelines and then be bolted together similar to the picture you are putting under your photo. so the question is will flanges in american standard fit in those eurpean ones? is there an eqvulant in both sides?

• You can look at ASME standard flanges B16.5 (from NPS 1/2 up to NPS 24) or large size flanges B16.47 (from NPS 26 up to NPS 60), to be compared with DIN standard flanges.

• Also refer to CR4 Thread: DIN Flange and ANSI Flange.

• You can find a lot of standards, codes, handbooks, and software for free download from that site: http://www.egpet.net/vb/index.php.

what is pcd for 42" class 900 flange with RTJ. and where can i get the dwg for the same.

what is the type 01B PN 10 flange

See Table 34 Dimensions of Class 900 Series A Flanges of ASME B16.47:

Free download : ASME Flanges Class (PN) & NPS (DN).

A telephone call to the local friendly Valves Distributor from where the valve was purchased will yield the answer.

<...can it hold 5575psi pressure or not...>

Be prepared to state the intended operating temperature range during the call.