304 stainless steel (sa249) versus a409 stainless steel

[mielke]

can anybody give me a quick difference between sa249 and a409 stainless steel tubes. comparing strength, max working temp and pressures, etc...

 

[EdStainless]

two very different alloys, an autenitic and a low alloy ferrtic.
What sort of application do you have in mind?

Start with the blue sheets from Alleagheny Ludlum.

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Plymouth Tube

 

[CoryPad]

Ed,

I think this is in reference to ASTM A 409/A 409M Standard Specification for Welded Large Diameter Austenitic Steel Pipe for Corrosive or High-Temperature Service, which is similar to ASTM A 249/A 249M Standard Specification for Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes.

 

[EdStainless]

tks Cory

To start with the scope of each, A249 only apples to 1/8" though 12" and A409 covers NPS 14 through 30.

The biggest difference is that A409 has provision for welding with filler metal, A249 requires all autogenous welds.

The only NDT in A409 is a pressure test, A249 has provision for Eddy Current testing.



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Plymouth Tube

 

[metengr]

Here is a tip, if you are interested in comparing strength at service temperatures between these two material specifications review ASME B&PV Code, Section II, Part D because this is where you will find pertinent allowable stress values. These values will not be found in the referenced ASTM/ASME material specifications.