If a standard B16.5 or B16.47 carbon steel flange is used in a vessel, does the UCS-66(c) impact test exemptions apply if the designer chooses to calculate the flange per App.2?
My position is: Yes and here is why.
Flanges evaluated per Appendix 2 must have their MDMT and impact test requirements determined per the appropriate material type Subsection-Part (UCS, UHA, etc.) as Appendix 2 does not address specific material requirements or Minimum Design Metal Temperature or impact test requirements. Therefore, for CS flanges (standard or app.2) the MDMT/impact-testing rules of UCS-66 apply in all cases. As such, UCS-66(c) applies whether the standard pressure-temperature rating is used or Appendix 2 is used to evaluate the flange. The key word in UCS-66(c)(1)(-a) and (-b) is “supplied.” There is no distinction between the method of evaluation in the text of the Code.
For example, an Appendix 2 design can be applied to an SA-105 B16.5 flange supplied in the as-forged condition. This flange would have an MDMT of 0°F without impact testing per UCS-66(c)(1)(-b).
Phil
My position is: Yes and here is why.
Flanges evaluated per Appendix 2 must have their MDMT and impact test requirements determined per the appropriate material type Subsection-Part (UCS, UHA, etc.) as Appendix 2 does not address specific material requirements or Minimum Design Metal Temperature or impact test requirements. Therefore, for CS flanges (standard or app.2) the MDMT/impact-testing rules of UCS-66 apply in all cases. As such, UCS-66(c) applies whether the standard pressure-temperature rating is used or Appendix 2 is used to evaluate the flange. The key word in UCS-66(c)(1)(-a) and (-b) is “supplied.” There is no distinction between the method of evaluation in the text of the Code.
For example, an Appendix 2 design can be applied to an SA-105 B16.5 flange supplied in the as-forged condition. This flange would have an MDMT of 0°F without impact testing per UCS-66(c)(1)(-b).
Phil
