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 that interconnects pieces or stages within a packaged equipment assembly.

Key changes to this revision include:
1) Additional of Appendix W – High Cycle Fatigue Assessment of Piping Systems
2) Metric conversion added for Table C-6, Moduli Table
3) Metric conversions added for Appendix C Thermal Expansion
4) Major updates to the stress tables in A-1, A-1M, K-1
5) Para. 323.2.2 Rules for Impact Testing of Materials was updated to correct inconsistencies, and incorporate current approaches to impact testing exceptions of materials
6) Reference to the new B31J-2017 added
7) Allow alternate rounding approaches for units of measurement
8) Update the Larson Miller constant for Grade 91 (9Cr-1Mo-V) material
9) Update Appendix D – Flexibility and Stress Intensification Factors
10) Add titanium Grade 12 to Table A-1 and Table A-1M

B31.3 is one of ASME’s most requested codes. 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.

Careful application of these B31 codes will help users to comply with applicable regulations within their jurisdictions, while achieving the operational, cost and safety benefits to be gained from the many industry best-practices detailed within these volumes.