Construction and repair of boilers and pressure piping systems is done under strict regulations set forth in the American Society for Mechanical Engineers (ASME) Boiler and Pressure Vessel Code and ASME B3 1 Code for Pressure Piping.
ASME Boiler and Pressure Vessel Code
The ASME maintains a Boiler and Pressure Vessel Code (B&PV Code) and a Code for Pressure Piping, both of which are recognized by the American National Standards Institute (ANSI). The ASME codes govern design, construction, maintenance, inspection and care of power boilers, heating boilers, nuclear power plant components, pressure piping systems, and pressure vessels operating at 103 kPa (15 lb/ in.2) and higher. Specifications for these codes are prepared and updated by volunteer committees rendering consensus of technical expertise. These codes are recognized and highly respected for the solid technical base they present.
The ASME Boiler and Pressure Vessel Code is referenced in the safety regulations of most states and major cities. It is also included by various federal agencies as part of their regulations, and is often used by authorities of other countries. An important aspect of the ASME code is that it requires third party inspection independent of the fabricator and user; inspection is commissioned by the National Board of Boiler and Pressure Vessel Inspectors (NBBPVI).
The ASME code is published in 11 sections, as outlined in Table B- 1. A new edition of the code is issued by the ASME every three years. Users may submit inquiries to the ASME at any time for clarification of requirements, or to pose other questions. Inquiries dealing with significant topics are given a case number, and both the question and ASME’s response are
regularly published in ASME Mechanical Engineering, and in separate booklet form as a supplement to the code. Subsequently, these case interpretations are carefully reviewed to determine revisions to the next editions of the code. As a result, it is important to work with the current issue of the code and to review any case interpretations that may have been published.
ASME 8-31 Code for Pressure Piping
The ASME Code for Pressure Piping, B 31, is published in six sections, as outlined in Table B-2. Each section prescribes requirements for design, materials, fabrication, erection, testing, and inspection of a designated piping system. Third-party inspection is not required under the Code for Pressure Piping. However, pressure piping external to a boiler is covered by the ASME Boiler and Pressure Vessel Code, and therefore, third-party inspection is required. Some sections of the Code for Pressure Piping require qualifications to be performed in accordance with other documents. Examples of documents that add to the total requirement are Section IX of the ASME Boiler and Pressure Vessel Code, and American Petroleum Institute (API) Standard 1104.
Reference: Linnert, George E; Welding Metallurgy: Fundamentals Vol. 1, 4th Edition, Miami, Florida: American Welding Society, 1995.