New version of ASME B31.3 has been issued.
In this version the table of Basic Allowable Stresses (A-1) has been totally revised. It has also been added a version with metric units (Table A1-M).
Also has been added the metric unit version of Table A-2 (Design Stress Values for Bolting Materials) and of the sample calculations for Branch connections (Appendix H).
Another change of B31.3 2013 is the Appendix N about  Application of ASME B31.3 Internationally.“ASME B31.3 contains requirements for piping typically found in petroleum refineries; chemical, pharmaceutical, textile, paper, semiconductor, and cryogenic plants; and related processing plants and terminals.  It covers materials and components, design, fabrication, assembly, erection, examination, inspection, and testing of piping.

This Code applies to piping for all fluids including: (1) raw, intermediate, and finished chemicals; (2) petroleum products; (3) gas, steam, air and water; (4) fluidized solids; (5) refrigerants; and (6) cryogenic fluids.  Also included is piping which interconnects pieces or stages within a packaged equipment assembly.

B31.3 is one of ASME’s most popular codes, widely adopted by jurisdictions worldwide.  It serves as a companion to ASME’s B31.1 Code on Power Piping as well as to the other codes in ASME’s B31 series.  Together, they remain essential references for anyone engaged with piping.”