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arrri
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Join Date: Oct 2011
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Inch & Diameter

12/19/2011 1:56 AM

in pipe scheduel 3" ,DN=80,ASME=88.9 but per inch is 25.4 and DN should be 76.2 ASME should be another number but from 4" to 36" DN calculate 4x25 and ASME 4x25.4 etc.any body knows how can i calculate pipe schedual and what is the reason for this diffrence between calculating.

thank you
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PWSlack
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#1

Re: INCH & DN

12/19/2011 5:55 AM

Triplicate thread alarm. Aaaarrrrooooooooooooooogaaaah!

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arrri
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#2
In reply to #1

Re: INCH & DN

12/19/2011 6:31 AM

I'm so sorry what should i do,this is for my question in 2 section?
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PWSlack
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#3
In reply to #2

Re: INCH & DN

12/19/2011 6:34 AM

Wait.

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PennPiper
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Engineering Fields - Piping Design Engineering - Retired Piper

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#4

Re: Inch & Diameter

12/19/2011 12:44 PM

This makes no sense at all!

"in pipe scheduel 3" ,DN=80,ASME=88.9 but per inch is 25.4 and DN should be 76.2 ASME should be another number but from 4" to 36" DN calculate 4x25 and ASME 4x25.4 etc.any body knows how can i calculate pipe schedual and what is the reason for this diffrence between calculating."

Why don't you find someone who speaks English real good and let them help you with the right words?

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arrri
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#5
In reply to #4

Re: Inch & Diameter

12/19/2011 1:14 PM

thank you but i think my question about pipe its not for my english grade, anyhow you good,im so bad

good for you
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arrri
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Posts: 13
#6
In reply to #5

Re: Inch & Diameter

12/19/2011 1:22 PM

please check pipe schedule,per inch is 25.4 mm but as i mentioned in pipe 3" DN is 80 instead of 76.2(3x25.4) what is the reason?my english better now duddd
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Anonymous Poster #1
#9
In reply to #4

Re: Inch & Diameter

12/20/2011 3:14 PM

PP:

I believe that you want someone who speaks English " really well".... not "real good"
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PennPiper
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#7

Re: Inch & Diameter

12/19/2011 3:00 PM

Okay, now I think I understand what you are asking.

You want to have a detailed explanation of why 3" (NPS) pipe is not 3" O.D. (it's 3.5") and why the metric equivalent 3" pipe (DN80) is not the absolute multiplier of the metric equivalent of 3 times the metric equivalent of 1". Is this right?

NPS = Nominal Pipe Size (US) For metric the term is "DN" = Diameter Nominal

Pipe sizes, along with the related pipe fittings, pipe flanges and valves are designated in both inches (NPS - Nominal Pipe Size) and metric units (DN - "Diameter Nominel"). The definition of the word "Nominal" is "In name only. It is not absolute.

Pipe is identified by "nominal" or "trade" names that are loosely related to actual dimensions. For instance, a 2-inch galvanized steel pipe has an inside diameter of about 2 1/8 inches and an outside diameter of about 2 3/8 inches. It is called "2-inch pipe" only for the sake of convenience.

There are the inch names for pipe products called NPS or "nominal pipe size" and their metric equivalents called DN or "diametre nominel". The metric designations conform to International Standards Organization (ISO) usage and apply to all plumbing, natural gas, heating oil, and miscellaneous piping used in buildings.

Beginning piping students all over the world seem to ask this same question and in most cases their instructors do not provide an adequate answer.

3" NPS Pipe is called 3" (In name only)

DN 80 Pipe is called DN 80 (In name only)

I hope this helps.

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arrri
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#8
In reply to #7

Re: Inch & Diameter

12/20/2011 1:01 AM

thank you dude, sorry for inconvenience.
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PennPiper
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#10
In reply to #8

Re: Inch & Diameter

12/21/2011 7:46 PM

arrri,

If you are interested there is lots of beginner, intermediate and advanced Piping Training material available on the web.

I suggest that you check out www.pipingdesigners.com.

There you will find some buttons near the top of the screen.

These buttons include:

"Training" = many articles about various phases of Piping Design and Engineering.

"Tips" = articles of general interest to all pipers

"Tools" = Excel Workbooks and Worksheets to help with problems pipers run into.

"Forum" = here you will find many different categories including "Technical Forum" with questions and answers about more than 550 topics.

I have had the honor to be able to assist the Owner & Founder of this web site. My contribution has been the writing of many of the articles and creating many of the excel "Tools". Most of these contributions include my biographical information. These also includes my e-mail address. If you are interested I would be happy to receive an e-mail from you and furnish advice and answers to your questions.

Pennpiper (aka: Jop)

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arrri
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#11

Re: Inch & Diameter

12/22/2011 12:12 PM

you are too kind buddy

thank you so much
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