B31.1

Power piping, unsurprisingly, is found in electric power generating stations, such as industrial and institutional plants, geothermal heating systems, and central and district heating and cooling systems. This places an exuberant amount of stress and pressure on the need to specify and adequately operate these systems, even beyond the stresses and pressure by which the piping intrinsically functions. These interests are reflected in the content of and changes made to ASME B31.1-2018: Power Piping, the standard for these systems.

Since any failure in power piping systems not only inhibits the piping’s performance locally but can also result in numerous people losing their power, heat, and air conditioning, it is crucial that they adhere to code. ASME B31.1-2018 is this code. As a section of the overall American Society of Mechanical Engineers Code for Pressure Piping, B31, ASME B31.1-2018 exists as its own document for power piping.

Specifically, it details the design, materials, fabrication, erection, test, inspection, operation, and maintenance of piping systems. Piping used with ASME B31.1-2018 includes pipe, flanges, bolting, gaskets, valves, pressure-relieving valves/devices, fittings, and the pressure-containing portions of other piping components.

ASME B31.1-2018 revises the 2016 edition of the same standard code for power piping, and, as the key document for the industry, it contains numerous changes crucial for keeping the standard current. In fact, there were so many changes made to this edition that, when listed at the beginning of the ASME B31.1-2018 document, the referenced locations of each change comprise three pages.

Some featured changes made to the ASME B31.1-2018 revision include:

Clarification that, where service requirements necessitate measures beyond those addressed in the code, such measures are to be specified by the engineering design.

New definitions for austenitizing, heat treatments, subcritical heat treatment, and heat treatments, tempering. Revisions to figures for code jurisdictional limits for piping examples to better convey the information they represent. New figure on “Code Jurisdictional Limits for Piping – HRSG – Desuperheater Protection Devices.”

Revised equation for the minimum wall thickness of straight pipe under internal pressure (including seamless, longitudinal welded, or spiral welded and operating below the creep range). In the section featuring this equation, nomenclature has also been alphabetized and W, the weld strength reduction factor, has been added.

Removed section 104.1.4 from ASME B31.1-2016, which covered equations specific to longitudinal-welded or spiral-welded pipe operating in the creep range.

Updates to the equation to stress due to occasional loads, which now includes the defined term Po representing the pressure coincident with the occasional load being evaluated in psi (kPa).

Inclusion of carbon-molybdenum steel in the list of steels in the carbide phase that may be converted to graphite upon prolonged exposure to high temperatures.

New subparagraph in the steel section discussing how carbon and low alloy steels can be susceptible to flow-accelerated corrosion (FAC) under certain conditions.

Inclusion of nickel alloys in the calculations for the forming strains of cold-formed areas of components.

Substantial updates to the section covering inspection and qualification of authorized inspectors for boiler external piping. Removed Mandatory Appendix J, “Quality Control Requirements for Boiler External Piping (BEP)” from ASME B31.1-2016.

New figure displaying the winding angle of filament-wound thermosetting resin pipe.

New Mandatory Appendix O, “Use of Alternative Ultrasonic Acceptance Criteria.”

New Mandatory Appendix P, “Metallic Bellows Expansion Joints.”

Removed Nonmandatory Appendix VI, “Approval of New Materials.”

As you can see, these changes are plentiful, and they touch the many facets of power piping covered by the standard document. Users can easily find any alteration made to the ASME B31.1-2018 revision by noting the number (18) in the margin. ASME B31.1-2018: Power Piping is available on the ANSI Webstore.

Read more at the ANSI Blog: Changes to ASME B31.1-2018: Power Piping https://blog.ansi.org/?p=158524

https://blog.ansi.org/2018/09/changes-asme-b31-1-2018-power-piping/

https://www.asme.org/products/codes-standards/b311-2018-power-piping

ASME B31.1-2018 Power Piping

ASME has been defining piping safety since 1922. ASME B31.1 prescribes minimum requirements for the design, materials, fabrication, erection, test, inspection, operation, and maintenance of piping systems typically found in electric power generating stations, industrial and institutional plants, geothermal heating systems, and central and district heating and cooling systems. It also covers boiler-external piping for power boilers and high-temperature, high pressure water boilers in which steam or vapor is generated at a pressure of more than 15 psig; and high temperature water is generated at pressures exceeding 160 psig and/or temperatures exceeding 250 degrees F. Key changes to this revision include: - New and updated figures for Code Jurisdictional Limits on Piping - New Mandatory Appendix on Metallic Bellows Expansion Joints - New Mandatory Appendix on Use of Alternative Ultrasonic Acceptance Criteria - Reference to ASME CA-1, Conformity Assessment Requirements ASME B31.1 is one of ASMEÆs most requested codes, widely adopted by jurisdictions worldwide. It is prominently referenced in ASMEÆs Boiler and Pressure Vessel Code, Section I. This Code serves as a companion to ASMEÆs B31.3 Code on Process Piping as well as to the other codes in ASMEÆs B31 series. Together, they remain essential references for anyone engaged with piping. Intended for manufacturers, designers, operators and owners of piping systems including, but not limited to, steam, water, oil, gas, and air services, plus all potential governing entities.

Some featured changes made to the ASME B31.1-2018 revision include:

• Clarification that, where service requirements necessitate measures beyond those addressed in the code, such measures are to be specified by the engineering design.
• New definitions for austenitizing, heat treatments, subcritical heat treatment, and heat treatments, tempering.
• Revisions to figures for code jurisdictional limits for piping examples to better convey the information they represent.
• New figure on “Code Jurisdictional Limits for Piping – HRSG – Desuperheater Protection Devices.”
• Revised equation for the minimum wall thickness of straight pipe under internal pressure (including seamless, longitudinal welded, or spiral welded and operating below the creep range). In the section featuring this equation, nomenclature has also been alphabetized and W, the weld strength reduction factor, has been added.
• Removed section 104.1.4 from ASME B31.1-2016, which covered equations specific to longitudinal-welded or spiral-welded pipe operating in the creep range.
• Updates to the equation to stress due to occasional loads, which now includes the defined term Po representing the pressure coincident with the occasional load being evaluated in psi (kPa).
• Inclusion of carbon-molybdenum steel in the list of steels in the carbide phase that may be converted to graphite upon prolonged exposure to high temperatures.
• New subparagraph in the steel section discussing how carbon and low alloy steels can be susceptible to flow-accelerated corrosion (FAC) under certain conditions.
• Inclusion of nickel alloys in the calculations for the forming strains of cold-formed areas of components.
• Substantial updates to the section covering inspection and qualification of authorized inspectors for boiler external piping.
• Removed Mandatory Appendix J, “Quality Control Requirements for Boiler External Piping (BEP)” from ASME B31.1-2016. New figure displaying the winding angle of filament-wound thermosetting resin pipe.
• New Mandatory Appendix O, “Use of Alternative Ultrasonic Acceptance Criteria.”
• New Mandatory Appendix P, “Metallic Bellows Expansion Joints.”
• Removed Nonmandatory Appendix VI, “Approval of New Materials.”

https://blog.ansi.org/2018/09/changes-asme-b31-1-2018-power-piping/