scope:

General

This Standard covers pressure-temperature ratings, materials, dimensions, tolerances, marking, testing, and methods of designating openings for pipe flanges and flanged fittings in sizes NPS ½ through NPS 24 and in rating Classes 150, 300, 400, 600, 900, 1500, and 2500. Flanges and flanged fittings may be cast, forged, or (for blind flanges and certain reducing flanges only) plate materials as listed in Table 1A.

Requirements and recommendations regarding bolting and gaskets are also included.

References

Referenced Standards. Standards and specifications adopted by reference in this Standard are shown in Annex G, which is part of this Standard. It is not considered practical to identify the specific edition of each standard and specification in the individual references. Instead, the specific edition reference is identified in Annex G. A flange or flanged fitting manufactured in accordance with earlier editions of the referenced standards and in all other respects conforming to this Standard will be considered to be in conformance with this Standard.

Codes and Regulations. A flange or flanged fitting used under the jurisdiction of the ASME Boiler and Pressure Vessel Code, the ASME Code for Pressure Piping, or a governmental regulation is subject to any limitation of that code or regulation. This includes any maximum temperature limitation, or rule governing the use of a material at low temperature, or provisions for operation at a pressure exceeding the pressure-temperature ratings in this Standard.

Applicable Ratings

The pressure-temperature ratings in this Standard are applicable upon its publication to all flanges and flanged fittings within its scope which otherwise meet its requirements. For unused flanges or flanged fittings maintained in inventory, the manufacturer of the flange or flanged fittings may certify conformance to this Edition provided he can demonstrate that all requirements of this Edition have been met. Where such components were installed in accordance with the pressure-temperature ratings of an earlier edition of this Standard, those ratings are applicable except as may be governed by the applicable code or regulation (see para. 1.2.2).

User Accountability

This Standard cites duties and responsibilities that are to be assumed by the user in the areas of application, installation, hydrostatic testing, operation, and material selection.

Quality Systems

Nonmandatory requirements relating to the product manufacturer's Quality System Program are described in Annex G.