2003 EDITION OF ASME B16.5 TO BE ISSUED IN NOVEMBER 3

[LSThill]

2003 EDITION OF ASME B16.5 TO BE ISSUED IN NOVEMBER

Highlights of changes from prior edition: The 2003 edition of ASME B16.5 (Pipe Flanges and Flanged Fittings) includes metric units as the primary reference units while maintaining U.S. customary units in either parenthetical or separate forms. Several new materials have been added to the standard. All pressure-temperature ratings have been recalculated using data from the latest edition of the ASME Boiler and Pressure Vessel Code, Section II, Part D. In addition, straight hub welding flanges have been incorporated as a new set of flanges in Classes 150 through 2500. There are also numerous requirement clarifications and editorial revisions.


LST

Contact Patricia Reddington, mailto:reddingtonp@asme.org for more information.

 

[StressGuy]

Metric as primary units, eh? Why?

So, what does a 150# Class flange become in metric, anyway?

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

All opinions expressed here are my own and not my company's.

 

[ADV]

ANSI150~1.6 MPa

 

[kenvlach]

150 psi = 1.034 MPa.

 

[LSThill]

HI kenvlach (Materials)


150 psi = 1034.2MPa

lst

 

[StressGuy]

Guys, that was a joke. I know how to convert psi to MPa. That's not what I was asking. Right now the table says CLASS 150, CLASS 300, etc. Those classes are based on the U.S. Customary system.

Are we really going to see the class 150 title changed to Class 1034.2? Doubtful.

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

All opinions expressed here are my own and not my company's.

 

[jsummerfield]

ANSI flange classes are not 150 pound or 300 pound they are Class 600. So, what is the corresponding pressure of an ANSI Class 600 carbon steel flange at 100 degree F? So me the 600.


John

 

[LSThill]

jsummerfield (Electrical)

RATING CLASS: 600, ASME B16.5a-1998
TEMP F -20 to 100 @psig: 1480/kPag: 10205.
NOTE: Full flange ratings per ASME B16.5, Table 2-1.1

LST

 

[jsummerfield]

You can see there is no obvious relationship between flange class and pounds per square inch. My point responds to Edwards rhetorical question. ANSI Class 150, 300, 600, 900, 1500, 2500 ... lack any real correlation with English, metric or SI units.

Why not use SI units? We are in a global economy where kPA, degree C and mm reign supreme. Our clients use SI units. Surely recent graduates are trained in SI units. Surely the Fundamentals of Engineering exam is in SI units.

I use millimeters for my home projects and work projects. I buy my Stanley and Chinese knockoff tape measures with dual inch/mm scales. Once you start using millimeters you will not want to mess with inches and fractions, feet, rods, chains, yards, ... Even miles become an issue as statute miles are cause confusion in the aviation and marine business where the nautical mile is king (60 minutes latitude is a nautical mile).

ANSI 600 is 1480 psig at 100 degree F in each of the English, metric and SI systems.


John

 

[StressGuy]

Well, this is probably going off topic a bit, but I'll have to disagree with the SI units business. I learned SI units back in college as theoretical information, like everything else in school.

The world that I know and work in is feet, inches, pounds, and psi. From my years of working with these, I know that 1500psi is some pretty high pressure and 10,000feet of pipe is a pretty long run. I have no feel for things like Newton or Pascals to know if 50 Newtons is a big or small load or if 50 Pascals is a large amount of pressure.

I've only been out of school for seven years, but I bet most engineers in the U.S. are similar to me. I had to work one project that was metric and it was a royal pain for everybody have to convert units back to English to get a feel for whether a number was big or small.

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

All opinions expressed here are my own and not my company's.

 

[jsummerfield]

lsthill, sorry for hijacking the topic.

Ed, I too live in Houston. Normally I work in Houston - sometimes even on Texas projects. Sometimes I use the former English system (almoste only Americans use it now). Many of my projects are for international sites and use standardized SI units.

I praise millimeters but still have a better since of psi than kPa. Your speedometer helps you to know that there is a 5/8 relationship between statute miles and kilometers as 160 km/h corresponds almost with 100 mph, right? By now you are accustomed to liters. They are nearly the same as a quart, right? 2.2 pound/kg is easy enough.

My present project is a very mixed bag. I am coming up to six years on a project in Mexico that uses kg/cm2, nearly the same as bar or atmospheres. They also use degree C and US gallons per minute. The Scotsmen on the platform with me talk about weight in stones and a couple of weeks in fortnights.

I will probably download B16.5 tonight as a pdf. I look forward to leaving this jobsite startup activity and beginning another project in the design stage where I can apply the new standard.


John

 

[mloew]

To add flummox to the fire: Let's not call it "imperial" units in the United States. I believe the correct terminology is "U.S. Customary System of units". I have heard it called "inch-pound" as well.

Best regards,

Matthew Ian Loew
"Luck is the residue of design."
Branch Rickey

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[jte]

Fawkes-

Hmmm... I've worked "English", "metric", and "SI" jobs. Do you buy your apples by the pound, kg, or N? Are your design pressures in kg/cm^2 or in Pa?

As for whether B16.5 is an ASME or ANSI document... From the forward to my 1996 edition:

"In 1982 American National Standards Committee B16 was reorganized as an ASME Committee operating under procedures accredited by ANSI..."

"Following approval by the Standards Committee and ASME, approval as an American National Standard was given by ANSI on October 3, 1996 with the new designation ASME B16.5-1996."

So its an ASME document accredited and/or approved by ANSI.

jt

 

[aclark]

Just for everyones information. The next edition of the ASME Code (all sections) the primary units will be in metric, abd the U S units will be in brackets. So we all had better get used to it.

 

[DSB123]

Fawkes,
You should bear in mind that if it was not for the old farts as you call them you would not be here probably.

And as far as the ASME question goes there are still a vast number of people in the Pressure systems community who refer to ANSI B36.10,ANSI B31.3, ANSI B16.5 etc which is the wrong designation now. Also there are many British engineers who refer to "withdrawn" British standards for new design work "because they have refered to them for years and have not checked if they are still valid or not.

 

[bvi]

Class and NPS are designations, not measurement units (e.g. Class 150 and NPS 4). Thus, there is no point in making a US Conventional Units to SI units conversion. As such, Class (e.g. Class 150) and NPS (e.g. NPS 4 for a pipe with a 4.5 inch OD) are used both in the SI unit portion of the new B16.5 standard and in the US Customary Units portion of the standard.

Note that Class pins down the geometry of the flange. The pressure rating depends upon the material of construction and the temperature.

 

[StressGuy]

Fawkes,

I believe the US did the same thing back in the 70's, passing some sort of law saying the SI would be the official system of measure, but it was never seriously implemented anywhere.

The reality is that in the U.S. our system of measure uses pounds, psi, feet, inches, etc. Call it by what ever name you want.

It seems odd to me then, that the AMERICAN Society of Mechanial Engineers and the AMERICAN National Standards Institute are making doucments with SI as the primary units.

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

All opinions expressed here are my own and not my company's.

 

[jsummerfield]

The non-profic American organization want their standards to continue to be among the world reference standards. Non profit companies like ASME, ISA, NFPA, ANSI, API, ASTM and IEEE have European and Japanese competitors like IEC, NEMUR, ISO, JIC, etc. They are working together to a large degree these years. However, the rest of the world uses SI units. The American code and standard agencies need to go SI to stay in the game.


John

 

[mloew]

Edward,

The Metric Conversion Act of 1975 (

http://www.usaid.gov/policy/ads/300/metricact.pdf)

is the law passed by congress that you refer to. Organizations that publish standards and specifications want to comply with the law so it can be referenced in government contracts and will also have worldwide applicability as suggested by John above.

Best regards,

Matthew Ian Loew
"Luck is the residue of design."
Branch Rickey

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.