ASME B16.5 (2017) - 904L forging spec

[marty007]

thread292-434856
thread794-342249

Well, I finally got a response from the ASME B16.5 code committee, and it isn't what I was hoping for:

Background:
- ASME B16.5 currently lists A479 as the forging spec for 904L material. This spec is titled: Specification for Stainless Steel Bars and Shapes for use in Boilers and Other Pressure Vessels. This isn't even a forging specification!
- I asked if we could use A182 instead. This is the most commonly used forging spec in ASME B16.5 for a wide range of materials.
- If you try to source an A479 904L flange, 95%+ of suppliers offer A182 instead and say they've never heard of A479 904L flanges.

Does anyone have any thoughts on why ASME B16.5 insists that A479 should be used instead of A182 as the forging spec for 904L?

 

[EdStainless]

Which version of A182 is SA182 currently referencing? They may not have moved to the one yet that includes 904L.
Remember that this alloy was moved there from the B specs. I am surprised that they don't refer you back to B/SB625 or one of those.

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P.E. Metallurgy

 

[marty007]

ASME IIA(2019) currently references A182-18 for SA-182.

I dug through some old editions of ASME IIA. 904L appeared in SA-182 in the 2004 Edition (2006 addenda).

 

[marty007]

There is such a mix-up with this material in the code...

If you look at the acceptable materials per ASME VIII-1, SA-479 isn't even an accepted material!

Per ASME IID, following are the accepted specs for ASME VIII-1 vessels:
[ul]
[li]SA-182 - Forgings[/li]
[li]SA-240 - Plate, sheet, strip[/li]
[li]SA-249 - Wld. tube[/li]
[li]SA-312 - Smls. pipe[/li]
[li]SA-312 - Wld. pipe[/li]
[li]SA-403 - Fittings[/li]
[li]SB-649 - Bar, wire[/li]
[li]SB-677 - Smls. tube[/li]
[/ul]

And yet if you want to get an ASME B16.5 weld neck flange, this must be supplied as A-479...

Sigh...