石油、石化和天然气工业.减压和减压系统

[中文适用范围]： 本文件适用于泄压和蒸汽减压系统。 虽然主要用于炼油厂，但它也适用于石化设施、天然气厂、液化天然气 (LNG) 设施以及石油和天然气生产设施。 所提供的信息旨在帮助选择最适合各种安装所涉及的风险和环境的系统。 本文件对 API Std 521 第 6 版（2014 年）进行了补充，其要求除本文件中规定的例外情况外均适用。 [外文原描述]： This document is applicable to pressure-relieving and vapour depressuring systems. Although intended for use primarily in oil refineries, it is also applicable to petrochemical facilities, gas plants, Liquefied Natural Gas (LNG) facilities and oil and gas production facilities. The information provided is designed to aid in the selection of the system that is most appropriate for the risks and circumstances involved in various installations. This document supplements API Std 521, 6th edition (2014), the requirements of which are applicable with the exceptions specified in this document.