Is ANSI flange equal to ASME flange 3

[ITBT]

Hi,

Wish to kown the difference btw ANSI weld neck flange and an ASME flange. Can anybody help? A lot of thanks!

 

[JStephen]

You might be more specific about the flange specifications.

The ASME B&PV Code includes material specifications for a lot of different material (plate, pipe, etc). Typically these specifications are identical to ASTM or ANSI standards, although they may not be as updated. So, there may be no difference. Read the ASME specification and it should indicate what it is based on. And check with the flange suppliers to see if the flange in question is dual-rated for both specifications.

 

[ijzer]

If you mean ASME B16.5 flanges , yes they are the same as ANSI B16.5.
About10 years ago the name of the standard was changed to ASME B16.5

 

[arto]

An ASME flange can also be a non-standard one designed to Appendix 2 of ASME B&PV Code Sec. VIII, Div. 1 [i.e., "do it yerself"]

 

[DSB123]

ijzer,
Do you know there are still (10 years on) who still call off ANSI B16.5 flanges and still produce piping specs stating ANSI ??? Even the larger Companies get it wrong.

 

[btrueblood]

It's only been ~6 years since the ANSI spec. went away.

 

[DSB123]

btrueblood,
Fine!! so its 6 years and not 10 so what!!! The fact is people still reference ANSI instead of the correct ASME.

 

[deanc]

Have a look at ASME SecII A&B. The Forward and Preface. Also the Forward of any of the Construction Codes. Table U-3 in SecVIII.

Think this will give you what you need. Some of the ANSI Stds are gone but referenced.

 

[btrueblood]

"Fine!! so its 6 years and not 10 so what!!! The fact is people still reference ANSI instead of the correct ASME. "


Chill man. No offense intended. Just pointing it out...I know of a lot of companies whose drawing revision backlog won't let them get around to updating some older prints that fast. And, a lot of people in the field "know what they mean" when a B16.5 flange is called out, to either ASME or ANSI.

In fact, some of the flanges you get delivered to you, and installed in your facility, were in fact probably made to the ANSI standard. Furthermore, flanges made to the current ASME standard will still fit up and work with flanges made in the 1930's. There just isn't much that can change regarding a pipe flange.

 

[bvi]

It is the same standard. It was simply an administrative action to change the title from ANSI B16.5 to ASME B16.5. ASME B16.5 remains an ANSI Standard (American National Standard). Same has occured with many other standards that are ANSI Standards that have been developed and maintained by ASME Code Committees.

 

[ITBT]

Hi, btrueblood,

Is that flange something like a 4-blot one?

 

[jsummerfield]

This thread presents a few issues that may be worth sharing.

For the cub, different bolt patterns exist for different sizes and (ANSI) classes. It gets trickier still at 24-inch and above.

Most engineers copy stuff from the clients contract, previous projects, etc. without obtaining a copy of the current standards. It is easy to at least find the current version of a standard on the web even if you have to use another source to obtain the copy.

Often we apply the standards that were current on the day that the contract was signed. I was working on a recent project for over six-years. That project was signed in about December 1997. We used the 1996 National Electrical Code for the entire period. If we bought something new in a later year - it was specified per the contract requirements. Often, the equipment supplier updates their products, thus might actually provide current stuff that incorporates recent code changes regardless of the purchase specification requirements.

John

 

[arto]

the 4-bolt flanges are SAE ones -
a different animal altogether
Anchor & Main mfg are suppliers

 

[btrueblood]

Um, careful, 3" pipe flanges and lower (150 or 125 lb. rating) also use four bolts.

SAE flanges are for hydraulic equipment.

Taking a step or two back, my opinion is that "standards" are created to provide a relatively non-changing reference design, so that parts can be interchanged between different manufacturers; also, there is an implied intent that the design not change radically over time. It's a bit peeving to me that a pipe flange, whose basic design has not changed in more than 70 years, has a "standard" that keeps being "updated" on a <10 year cycle. Seems a bit like a stockbroker churning an account.

 

[tickle]

BTrueBlood - I am all for standards to be changed to reflect the way things actually are or should be, i.e. making the standard more practical and applicable.

For instance, lets look at API 6D and B16.5. These two standards have different pressure deratings at elevated temperatures with the flanges having a higher pressure rating (in the copies that I use). Yet pipework is generally limited by the flanges not the valves, every one just specifies that valves are rated to B16.5 pressures and the valve manufacturers just make them.

Also, one of my other soap box items, why do the pressure deratings for flanges begin at 38degC, whereas the piping and pressure vessel codes start at much higher (and practical) temperatures (I am not a mechanical engineer so do not the detailed mathematics). There are not many places in the world that the design temperature in full sun is below 38degC.

I am impressed by the way the Australian Piping standard AS2885 permits you to not derate carbon steel flanges and valves on station pipework up to 120 degC.

 

[arto]

I mean the square/rectangular 4-bolt ones are SAE.
[

http://www.anchorflange.com/catalog/Catalog.pdf

http://www.mainmfg.com/

]

The latest ASME B16.5 is in Metric, with US/English units in the appendix.

[Not much different than my 1957 Ladish catalog - must be 'cuz most flange manufacturing & use is in "Metric Countries" now.]

Merry Christmas!! ;-)

 

[GenB]

allright, allright
Be carefull with your purchases and markings,
(If you are an ASME Accredited Mfr)
If you are doing things right, now you can not use
the ASME Sec II, The fabrication Sections of the Code
also specify the ANSI standard of the materials as are the B16
Flanges has to be marked: with the SA or SB xxx
the ANSI Specification as B16.xx, the weight or pressure as
150; 300; 3000#...; mfrs name initials or logo,
IF NOT: YOU ARE VIOLATING THE CODE,
do not get cought!
GB

 

[kander]

I have a drawing in front of me calling up a 22" ASME B16.5 Flange.

I can't find any spec for a 22" flange. Does anyone know of this flange size and where I could get physical dimensions for it?

 

[arcer]

Are you sure it's not a typo on the drawing?

 

[kander]

Apparently not a typo. The drawing (and referenced drawings) calls a class #300 22" RF Flange.

It would require to be a weld neck flange mating with a pipe with ID=527.2mm & OD=559mm. (ID=20.75" & OD=22" for you USA types!) Anyone heard of this?

Out of interest, a very reputable manufacturer for the oil & gas industry is still calling "ANSI" for their flanges.