316SS dual certified for wall thickness cals ASME B31.3

[17092003]

When using material 316SS dual cerified for wall thickness calculations in accordance with ASME B31.3, shall the mechanicals of 316SS i.e. 20ksi at room temperature be used.

Thanks

 

[XL83NL]

Do you mean if its allowed within B31.3, when calculating wall thicknesses for dual certified ASTM (which spec by the way?) 316/316L, to use the 'higher strength' grade for the calcs?
If you're using ASTM A312 TP316/316L pipe; yes, since the material meets both grades, hence also the higher stress allowables (please note that Ive assumed you meant stress allowables rather 'mechanicals' in your OP).

The calculation(s) shall be performed for the temperatures foressen; if your system is running at higher temperatures, than the calcs also have to be done for those temperatures.

 

[17092003]

Grades are as follows -
ASTM A312 TP316L (basic allowable 16.7ksi) and ASTM A312 TP316 (basic allowable 20ksi.

Yes for basic allowable.

Hence for 316SS dual certified material 20ksi basic allowable to be used at temperature for wt calculation.

thanks

 

[moltenmetal]

For 316/316L dual grade, the stress values for 316, i.e. the higher stress values, can be used to 1000 F. Beyond 1000 F, you need to use the LOWER stress values, i.e. the 316L values. B16.5 flanges must be H grade above 1000 F.

 

[metengr]

There are no allowable stress values for any L grades in B31.3, Table A-1. As mentioned above, if this is a dual certified stainless, and carbon is 0.04% by mass or higher, the allowable stress posted in Table A-1 would be used even beyond 1,000 deg F (538 deg C) for dual certified material.