B16.5 Flange Ratings 3

[PSP113]

Does anyone know the difference between A182 F316 and A182 F316L Flanges? They have the same amount of Cr, Ni, and Mo, but have different pressure ratings and they are categorized in different material groups.

 

[Bonswa]

This should cover it.

Grade 316 is the standard molybdenum-bearing grade, second in importance to 304 amongst the austenitic stainless steels. The molybdenum gives 316 better overall corrosion resistant properties than Grade 304, particularly higher resistance to pitting and crevice corrosion in chloride environments.

Grade 316L, the low carbon version of 316 and is immune from sensitisation (grain boundary carbide precipitation). Thus it is extensively used in heavy gauge welded components (over about 6mm). There is commonly no appreciable price difference between 316 and 316L stainless steel.

 

[JLSeagull]

Also check into dual certified 316/316L. Dual certified flanges are available from several suppliers.

See thread330-159413

http://www.spiusa.com/Ref001/austenitic.html

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[DVWE]

As Bonswa has indicated, the 316L has lower carbon and therefore has a lower rated tensile and pressure ratings.