36" SLIP-ON FLANGE 3

[Javierr]

Hello

I have been trying to get 36" SLIP-ON flange dimensions on ASME b16.47 standard, but it seems it only specifies welding neck and blind flanges (not like ASME b16.5 for flanges under 24 inches, which specifies dimensions for all kinds of flanges). Does it mean that there are no flanges with this diameter supported or made under ASME b16.47?

Thanks!

 

[MJCronin]

Things get a little strange for flanges above 24" NPS... You have to pay strict attention to the details of the standard you specify... are you interested in ASME Series A or Series B ?... how about API-605 ???

The fine people at "TEXAS FLANGE" are very helpful and can answer most questions. Take a look at their FAQs .....

https://www.texasflange.com/

In response to the more common question: How do I call out a slip on flange above 24"? they state:

That depends entirely on what you are trying to accomplish. If you want a part that is automatically covered under ASME Code, then forget Slip Ons and opt for a Weld Neck from B16.47 Series A or B. If you don’t need to meet code or can run the calculations for your application, then the options open up:

For the Standard 150# drilling we offer the “Class 125/ 150#” series. These are made per B16.1 which is a Cast Iron Spec. We make them most often in Carbon Steel per A105. In addition, we offer them in Stainless 304, 316, and all the other alloys too. Since the spec is for Cast Iron and the applications in industry usually call for another material these are made “per B16.1 Dimensions only.” There is also a much less commonly used Class 250 option available.

There are also 150#, 300#, 400#, 600#, and 900# Slip Ons that were designed by Tube Turns to match the MSS-SP-44 spec (which was almost 100% brought into ANSI B16.47 under Series A.) These were originally designed to meet ASME Code of the time, but quite some time has passed since then and as a result in many cases they do not meet current design criteria. Nevertheless, they are used on a frequent enough basis that we stock the contoured forgings in A105 and do a decent amount of business getting rolled rings to make them in other materials.

We have also been asked to make Slip Ons to match the B16.47 Series B dimensions. For this there is an agreed upon industry standard method that provides no calculations but has garnered wide acceptance. The basic design includes cutting down the weld neck forging and opening the ID.

Still more options remain as Taylor Forge designed many “Boiler Code” flanges that serve to add Slip On options in various classes. These parts are drilled per their design and do not match any other standard. The classes offered are 75, 175, and 350. For the dated information on pressure-temperature allowance see Taylor Forge Catalog 541 or contact us

Finally, the American Waterworks Association (AWWA) under their spec C207 has designs on a series of plate Slip-on flanges in Class B, D, E, and F. They also have hubbed Slip Ons in Class D and E.

Tell us more about your project and the choices that you are making..

What is the design pressure and temperatures of your piping system ?

MJCronin
Sr. Process Engineer

 

[Javierr]

Thanks MJCronin!

The truth is I don't have any information about the requirements of the flange. Our commercial department bought 36 inches Slip-on flanges, and on the supplier's certificate it says is under B16.47 (it also says it's under B16.5 among others, so they probably just put all the code/standards without checking). From what I can see then, B16.47 doesn't cover slip-on flanges above 24", and they probably fabricated a flange according to welding neck dimensions (OD, ID, Thickness, Bolt diameter). But I wonder which dimension they used for length through hub. About API 605 that you mention, I can't find the document but the B16.47 series B, are both the same??

Thanks!

 

[MJCronin]

Will your "Commercial Department" accept blame if your mystery flange fails and someone is killed ?? ...... I doubt it ...

...or will they finger you or some other inexperienced young engineer who is set-up as "the engineer of blame"...???

Call Texas Flange and talk with the experts ...

Be respectful and come back to this thread with what you find !!!

MJCronin
Sr. Process Engineer

 

[BJI]

You could check if it matches the MSS-SP-44 dimensions prior to the 1970 edition, not that it will help at all. Try and design the flange or reject it.

 

[StressGuy]

Why would a "commercial department" by anything without a spec that spells out what is supposed to be supplied? As MJCronin alludes to, choosing a flange is an engineering decision. A "commercial department" should be taking that decision/spec and finding a supplier to provide it at a competitive price.

You say you are trying to get dimensions for these flanges, I'm curious what your role with them is.

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

"All the world is a Spring"

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