本文件规定了ISO？13623中定义的石油和天然气工业管道运输系统中使用的碳钢和低合金钢锻造法兰的技术要求。 本文件适用于焊颈法兰和盲法兰（全端面、凸面和RTJ坡口）以及锚定法兰、旋转环法兰和孔板法兰。 本文件指定了符合行业需要的法兰类别，以匹配ISO？3183管道。这些法兰适用于正常和低温环境，并包括酸性环境所需的补充要求。 本文件不包括工厂焊接延伸件、螺栓材料、垫圈、滑动法兰或法兰配件的材料或附件。 本文件不适用于阀门、泵或其他设备的整体铸造或锻造法兰。 本文件不包括法兰类别或压力等级的选择。ISO？7005-1中列出并适用于本文件的尺寸和压力等级如下: -DN？10？（NPS？1/2）至DN？1500？（NPS？60）； -零件号20（150级）、零件号50（300级）、零件号100（600级）、零件号150（900级）、零件号250（1500级）、零件号420（2500级）。

This document specifies the technical requirements for carbon steel and low-alloy steel forged flanges for use in pipeline transportation systems for the petroleum and natural gas industries as defined in ISO？13623. This document applies to weldneck and blind flanges (full face, raised face, and RTJ groove) as well as anchor, swivel-ring flanges and orifice flanges. This document designates those categories of flanges that meet the industry's need to match ISO？3183 pipe. These flanges are for normal and low-temperature service and include supplementary requirements where required for sour service. Materials for, or the attachment of, factory-welded extensions, bolting materials, gaskets, slip-on flanges or flanged fittings are not covered by this document. This document is not applicable to integrally cast or forged flanges for valves, pumps or other equipment. This document does not cover the selection of the flange category or pressure class. Sizes and pressure classes listed in ISO？7005-1 and applicable to this document are as follows: —？DN？10？(NPS？1/2) to DN？1500？(NPS？60); —？PN？20 (class？150), PN？50 (class？300), PN？100 (class？600), PN？150 (class？900), PN？250 (class？1500), PN？420 (class？2500).