ISO 23251:2019

Petroleum, petrochemical and natural gas industries — Pressure-relieving and depressuring systems

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.

Industries du pétrole, de la pétrochimie et du gaz naturel — Systèmes de dépressurisation et de protection contre les surpressions

General Information

• Status: Published
• Publication Date: 17-Mar-2019
• ICS: 75.180.20 - Processing equipment
• Technical Committee: ISO/TC 67/SC 6 - Processing equipment and systems
• Drafting Committee: ISO/TC 67/SC 6/WG 12 - Pressure-relieving and depressuring systems
• Current Stage: 9020 - International Standard under periodical review
• Start Date: 15-Jan-2024
• Completion Date: 15-Jan-2024

Relations

• Revises: ISO 23251:2006/Amd 1:2008 - Petroleum, petrochemical and natural gas industries — Pressure-relieving and depressuring systems — Amendment 1
• Effective Date: 23-Apr-2020
• Revises: ISO 23251:2006 - Petroleum, petrochemical and natural gas industries — Pressure-relieving and depressuring systems
• Effective Date: 23-Apr-2020

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 23251
Second edition
2019-03
Petroleum, petrochemical and natural
gas industries — Pressure-relieving
and depressuring systems
Industries du pétrole, de la pétrochimie et du gaz naturel — Systèmes
de dépressurisation et de protection contre les surpressions
Reference number
ISO 23251:2019(E)
©
ISO 2019

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ISO 23251:2019(E)

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ii © ISO 2019 – All rights reserved

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ISO 23251:2019(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Supplements to API Std 521, 6th edition (2014). 2
4.1 General requirements . 2
4.2 Chemical reaction . 2
4.3 Fires . 2
4.4 Causes for vacuum . 3
4.5 Considerations for individual PRDs . 3
4.5.1 General. 3
4.5.2 Multiple PRDs . 3
4.6 Piping . 3
4.6.1 General. 3
4.6.2 Backpressure . 3
4.6.3 Line sizing . 3
4.6.4 Multiple relief scenarios . 3
4.6.5 Reaction forces .
...