石油和天然气工业.管道运输系统用工厂弯头、配件和法兰.第3部分:法兰

[中文适用范围]： 本标准规定了石油天然气工业管道输送系统用碳钢和低合金钢锻制法兰的技术要求。 本标准适用于对焊法兰和盲板法兰（全面法兰、凸面法兰和RTJ沟槽法兰） ）以及锚固法兰、旋转环法兰和孔板法兰。 本文件指定了满足行业需要的法兰类别，以满足酸性环境的要求。 本文件不涵盖工厂焊接加长件、螺栓材料、垫片、滑套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。 本文件不涉及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)； ——PN 20（150 级）、PN 50（300 级）、PN 100（600 级）、PN 150（900 级）、PN 250（1500 级）、PN 420（2500 级）。 [外文原描述]： 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).