scope:

The bolted flange joint assembly (BFJA) guidelines described in this document apply to pressure-boundary flanged joints with ring-type gaskets that are entirely within the circle enclosed by the bolt holes and with no contact outside this circle.¹ By selection of those features suitable to the specific service or need, these guidelines may be used to develop effective joint assembly procedures for the broad range of sizes and service conditions normally encountered in industry.

Guidance on troubleshooting BFJAs not providing leak-tight performance is also provided in this document (Appendix P).

¹ Rules for design of bolted flanges with ring-type gaskets are covered in Mandatory Appendix 2 of ASME Boiler and Pressure Vessel Code, Section VIII, Division 1; see also Nonmandatory Appendix S for supplementary considerations for bolted flanges that are helpful to the designer of Appendix 2 flanges.