ASME B16.5 / ASME B16.47 / API 6A / BS 3292 / EN 1092-1 / JIS


 Flanges dimensions and weights are defined by the following key norms:

  • ASME B16.5: all flanges, 1/2" - 24"This Standard covers the pressure-temperature ratings, materials, dimensions, dimensional tolerances, marking, testing, and methods of designating openings for steel flanges and flanged fittings. ASME B16.5 focuses on flanges and flanged fittings manufactured out of cast or forged materials, and blind flanges and specific reducing flanges from cast, forged, or plate materials. The standard also foresees requirements and recommendations related to flange bolting, flange gaskets, and flange joints. ASME B16.5 applies both to carbon steel flanges and stainless steel flanges.

 ASME B 16.5 flanges dimensions and weight.pdf

  • ASME B 16.47-Series A / B: blind and welding neck flanges 26’’-60’’: This Standard covers the dimensional tolerances, pressure-temperature ratings, materials, dimensions, testing and marking for steel flanges in sizes between NPS 26” and NPS 60” and in Classes 75 to 900. Flanges may be manufactured out of cast and forged materials, or plate (in the sole case of blind flanges). The standard also foresees requirements and recommendations related to bolting and gaskets. Note: Most of the MSS-SP44 have been included in ASME B16.47 Series A specifications, whereas the API 605 specifications have been incorporated into ASME B16.47 series B. They have also added Blinds to these two specs.

 ASME B 16.47 A-B flanges dimensions and weight.pdf

  • ASME B16.36: orifice flanges: This Standard covers flanges (similar to those covered in ASME B16.5) that have orifice pressure differential connections. The coverage of ASME B16.36 is limited to the following: (a) Welding Neck Flanges Classes 300-2500 (b) slip-on and threaded Class 300.

 ASME B 16.36 flanges dimensions and weight.pdf


  • ASME B16.48: Spectable blinds, spades, spacer ringsThis norm covers the dimensions, marking, pressure-temperature ratings, materials, dimensional tolerances and testing for line blanks in sizes between NPS 1/2 and NPS 24 for installation between ASME B16.5 flanges in the classes from 150 to 2500.

 ASME B 16.48 spectable blinds dimensions and weight.pdf

  • BS 3293: slip on, welding neck flanges 26" - 60"

 BS 3293 flanges dimensions and weight.pdf


  • API 6A

 API 6A flanges dimensions and weight.pdf

  • EN 1092-1 / DIN / UNI: Steel flanges and their joints - Circular flanges for pipes, valves, fittings and accessories


 EN 1092-1 flanges dimensions and weight.pdf (source: Ferrari Flanges, Italy)


  • JIS B2220: welded pipe flanges

    See size chart here
  • GOST 12820-80, 12821-80: Russian pipe flanges standard for flat and welding neck type



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