ISO 23251:2019 PDF

Scope: 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.

ISO 23251:2019 Referenced Document

API Std 521
EN 764-7 Pressure equipment - Part 7: Safety systems for unfired pressure equipment
ISO 15649 Petroleum and natural gas industries - Piping
ISO 25457 Oil and gas industries including lower carbon energy — Flare details for general refinery and petrochemical service*， 2023-10-01 Update
ISO 28300 Petroleum, petrochemical and natural gas industries - Venting of atmospheric and low-pressure storage tanks; Technical Corrigendum 1

2019 ISO 23251:2019 Petroleum, petrochemical and natural gas industries — Pressure-relieving and depressuring systems
2008 ISO 23251:2006/Amd 1:2008 Petroleum, petrochemical and natural gas industries - Pressure-relieving and depressuring systems; Amendment 1
2007 ISO 23251:2006/cor 1:2007 Petroleum, petrochemical and natural gas industries - Pressure-relieving and depressuring systems; Technical Corrigendum 1
2006 ISO 23251:2006 Petroleum, petrochemical and natural gas industries - Pressure-relieving and depressuring systems