Joint Efficiency

Previous API editions did include joint efficiencies:

But the more recent editions indirectly account for it through the allowable stress/prescribed radiograpy. There are only standard rules for radiography and no "options" similar to the ASME BPVC. Note, however, that in Appendix A - Optional Design Basis for Small Tanks (2007 - 2008a), the joint efficiency factor shall be 0.85 with the spot radiography required by A.5.3. By agreement between the Purchaser and the Manufacturer, the spot radiography may be omitted, and a joint efficiency factor of 0.70 shall be used.