Greetings,

I am a little perplexed by the following sentence found in ASME B31.3 Appendix S, Clause S301.2 (p.434 of B31.3-2014):

"For example, ASME B16.5 requires a minimum of Class 300 for ASTM A105 flanges."

I have attempted a glance through ASME B16.5-2013 but could not find any reference to such a limit.

Can anyone shed some light on this?

Thanks.

"For example, ASME B16.5 requires a minimum of Class 300 for ASTM A105 flanges."

This statement is valid only for the example given in Appendix S. For the given pressure and temperature of the system, the flanges should be at least Class 300. A Class 150 is not appropiate for this system.

Thank you Dan, it is seemingly obvious now.