Process piping transports fluids in a range of locations—most notably, petroleum refineries, onshore and offshore petroleum and natural gas production facilities, food and beverage processing facilities, and chemical, pharmaceutical, textile, paper, ore processing, semiconductor, and cryogenic plants. Due to this ubiquity, ASME B31.3-2018: Process Piping applies to systems that transport chemicals, petroleum products, fluidized solids, refrigerants, cryogenic fluids, and gas, steam, air, and water.
ASME B31.3-2018 is part three of the overarching ASME B31 Code for Pressure Piping. While being a Code Section and typically referred to as a Code, ASME B31.3-2018 is also an American National Standard. It prescribes guidelines for materials and components, design, fabrication, assembly, erection, examination, allowable stress, acceptance criteria, and testing of process piping to aid numerous groups. This includes the owner of the piping installation, as well as the designer, owner’s inspector, and manufacturer, fabricator, and erector.
ASME B31.3-2018 revises the 2016 edition of the same standard for process piping. Some changes made to the latest edition of the standard include:
- Text was added to “General Statements” in Chapter 1, “Scope and Definitions,” to note that the owner of a piping installation can designate a representative to carry out selected responsibilities of ASME B31.3-2018, but “the owner retains ultimate responsibility for the actions of the representative.”
- The standard clarifies that it was developed considering piping found in processing plants and terminals across numerous industries.
- Definitions were added for owner, readily accessible (for visual examination), and representative.
- External vortex shedding and acoustically induced vibration were added as sources of impact for vibration that the piping is to be designed, arranged, and supported to eliminate.
- Rules for the use of piping components not listed in Table 326.1, “Component Standards,” were altered.
- Weld joint strength reduction factor, W, was included as an allowance for pressure and temperature variations.
- A new row for Carbon Steel was added in Table 302.3.5, “Weld Joint Strength Reduction Factor, W.”
- In section 311.2, which covers “specific requirements” for welded joints, paragraphs on welds for category D fluid service, severe cyclic conditions, and elevated temperature fluid performance were removed.
- Table 314.2.1, which previously was previously the “Minimum Thickness of External Threaded Components,” is now the “Minimum Schedule of Components With External Threads.”
- ASME B18.31.2 was listed under Table 361.1, “Component Standards,” as the standard for “Continuous Thread Stud, Double-End Stud, and Flange Bolting Stud (Stud Bolt) (Inch Series).”
- The scope of Chapter IX, “High Pressure Piping,” was revised in its entirety.
- Text on fatigue analysis for unlisted high pressure piping components was added.
- Note that the use of the word “pipe” does not include “tube” or “tubing” in section K314 on “Threaded Pipe Joints.”
- Guidelines regarding flared end tubing joints were added to K315, “Tubing Joints.”
- Section K320, “Analysis of Sustained Loads,” was added.
- Section K326.4, “Repair of Piping Components By Welding,” was updated to highlight the importance of the owner’s approval.
- Table C-6M, “Moduli of Elasticity for Metals (SI Units),” was added.
- Examples of rounding for piping that has been placed in service were added as new section F300.1.4.
- General statements were added in Appendix F, “Guidance and Precautionary Considerations.”
- Appendix W, “High-Cycle Fatigue Assessment of Piping Systems,” was added.
- Appendix Z, “Preparation of Technical Inquiries,” was revised in its entirety.
Users should note that only a portion of the changes to ASME B31.3-2018 are included in the list above. All changes made to this American National Standard are listed just after the introduction in the document, where the location of each alteration is laid out. Furthermore, the ASME B31.3-2018 document clearly notes wherever a revision has taken place by a margin note, (18).
If you are interested in the changes made to the previous publication of this standard, you can refer to our blog post on ASME B31.3-2016 – Process Piping Changes.
ASME B31.3-2018: Process Piping is available on the ANSI Webstore.