ASME to Publish ASME B16 Standards Revisions This Year

ASME to Publish ASME B16 Standards Revisions This Year ASME to Publish ASME B16 Standards Revisions This Year ASME to Publish ASME B16 Standards Revisions This YearJune 17, 2016 ASME Standards Certification is preparing to issue revised versions of three of its ASME B16 Standards, which have been defining and ensuring piping safety for nearly 100 years. The new versions of the standards - ASME B16.5, B16.34 and B16.47 - were finalized last month and will be published concurrently later this year.ASME developed these three standards to provide industry with technical guidelines and requirements regarding the use of flanges and valves ranging from nominal pipe sizes (NPS) NPS to NPS 60. The B16 Standards Committee and Subcommittees C and N provide important guidance on pressure-temperature ratings, marking, materials, dimensions, and testing for valves and flanges through these standards.ASME B16.5 Pipe Flanges and Flanged Fittings - one of ASMEs fruchtwein requested p roduct standards because it covers a large range of sizes and pressure temperature ratings - covers pipe flanges and flanged fittings for flanges with rating class designations 150, 300, 400, 600, 900 and 1500 in size categories NPS through NPS 24. The standard also applies to flanges with rating class designation 2500 in sizes NPS through NPS 12. Materials covered in the standard include forged, cast and plate carbon, low alloy, stainless steel and nickel alloys. The second of the three standards, ASME B16.34 Valves - Flanged, Threaded and Welding End, applies to new valve construction requirements. It covers pressure-temperature ratings, nondestructive examination requirements, testing and marking for cast, forged and fabricated valves - including flanged, threaded, welding end or flangeless valves - constructed of carbon steel, low alloy steel, stainless steel or nickel-base alloys. The ASME B16.47 Large Diameter Steel Flanges standard covers pressure-temperatur e ratings, materials, dimensions, tolerances, marking and testing for welding neck and blind pipe flanges NPS 26 through NPS 60. It encompasses flanges with rating class designations 75, 150, 300, 400, 600 and 900, and includes requirements and recommendations regarding flange bolting, flange gaskets and flange joints. Dimensions for raised face (RF) and ring joint gasket facings are addressed in the standard, as are materials including forged, cast and plate carbon, low alloy, stainless steel and nickel alloys. ASME publishes the three standards simultaneously because they are so interrelated. In fact, they started as a single standard, B16e, handled by one B16 Subcommittee. In 1920, the American Engineering Standards Committee organized Section Committee B16 to unify and further develop standards for pipe flanges and fittings. Section Committee B16 soon formed subcommittees and, in 1923, Subcommittee 3 began developing the first edition of B16e, which welches eventuall y approved in 1927. The 1932 edition of B16e contained flanged fittings with integral bases, but did not include pressure-temperature ratings for alloy steel flanges and fittings, Class 2500 flanges, or Class 1500 flanges between NPS 14 and NPS 24. Revisions in the 1939 edition, resulting from suggestions from Committee members and users from industry, addressed these shortcomings, and included welding neck flanges and dimensions for loose ring type flange joints. Due to the quickly developing field of welding technology, the revised version also covered welding neck flanges for the first time.The outbreak of World War II had a significant impact on the development of B16 Standards because it affected the price and availability of materials, especially alloys. In August 1942, the War Production Board requested a review of measures to conserve vital materials in piping components, appointing a special War Committee of B16. The War Committee operated under War Standard P rocedure and developed increased pressure-temperature ratings for all materials and pressure classes except Class 150, and added a table of metal wall thickness for welding-end valves. Their revisions first appeared in the Supplement 1 to B16e-1939. In 1943, this supplement welches issued as a full standard, B16e-5-1943, which welches the first standard to include details for the construction of flanged and butt-welding end valves. The 1953 edition of B16e (re-designated B16.5), which incorporated the revisions introduced by the special War Committee of B16, also recognized the use of new materials, included a general rating method, and expanded coverage of welding end preparations. Two appendices, which were added in the 1957 edition, defined qualifications for gaskets other than ring joint and delineated the method for calculating bolt lengths.Other key years in the development of the B16.5 and B16.34 standards include 1968, the final year that the B16.5 standard incor porated construction for valves, flanges and flanged fittings 1973, the year that B16.5 and B16.34 editions introduced several major changes, including the addition of a ceiling pressure that materials could not exceed 1977, the year that B16.34 edition began covering all valve construction requirements including flanged valves and B16.5 became the stand-alone document for flanges and flanged fittings construction details 1981, when the B16.5-81 and B16.34-81 editions included nickel alloys for the first time and 1988, when the B16.34 standard began including details for threaded and socket-welding end valves and started covering limited pressure class valves. A subgroup of B16 Subcommittee C began work on the B16.47Large Diameter Steel Flangesstandard in November 1980 in an effort to standardize dimensions within the industry for materials covered by B16.5 for NPS 26 to NPS 60 flanges. The first draft was developed in December 1982, and went through subsequent drafts be fore the first edition was published in 1990. The B16.47 Standard was approved as an American National Standard in June 1990 following approval by ASME and the ASME B16 Standards Committee (formerly the American National Standards Committee B16).The new editions of ASME B16.5, B16.34, and B16.47, which are expected to be published this fall, will incorporate several important revisions, such as the inclusion of NPS 22 in B16.5 the alignment of the pressure-temperature tables in B16.5 and B16.34 the inclusion of low temperature valves and expansion of coverage up to NPS 60 in B16.34 and the addition of pressure-temperature table modifications to B16.47.For more information on the forthcoming 2016 editions of ASME B16.5, B16.34, and B16.47, contact Richard Lucas, Standards Certification, by e-mail at lucasrasme.org. For more information on ASME Standards Certification, visit /codes-standards.(This article was written with advice and review by Guy Jolly, member of B16 Su bcommittee C and B16 Subcommittee N.)Richard Lucas, Standards Certification