ISO 25457-2023 PDF

Full title and description

Oil and gas industries including lower carbon energy — Flare details for general refinery and petrochemical service. ISO 25457:2023 provides requirements and guidance for the selection, design, specification, operation and maintenance of flares and associated combustion and mechanical components for petroleum, petrochemical and natural gas facilities, with guidance applicable primarily to onshore facilities and supplementary guidance for offshore use.

Abstract

This International Standard specifies requirements and gives guidance for the selection, design, specification, operation and maintenance of flares and related combustion and mechanical components used in pressure-relieving and vapour-depressurizing systems for the petroleum, petrochemical and natural gas industries. It is intended primarily for onshore facilities while including guidance relevant to offshore applications and is issued as a supplement to API 537 (3rd edition, 2017) where indicated.

General information

• Status: Published.
• Publication date: 13 October 2023 (effective/published date).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 75.180.20 (Processing equipment).
• Edition / version: Edition 2 (2023).
• Number of pages: Catalogued as 2 pages in the ISO record (note: national adoptions or published adoptions/annotated versions may report different page counts).

Scope

This standard covers the selection, mechanical and combustion design details, specification, operation and maintenance practices for flares and associated equipment used in pressure-relief and vapour-depressurizing systems in petroleum, petrochemical and natural gas industries. While primarily aimed at onshore refinery and petrochemical service, it also provides guidance relevant to offshore applications and is published as a supplement to API 537 (3rd edition, 2017) including its addenda where applicable.

Key topics and requirements

• Selection and specification of flare mechanical components (stacks, tips, piping, seals).
• Combustion system design and performance criteria (pilot systems, purge, ignition, smokeless operation where applicable).
• Design guidance for relieving and vapor-depressurizing system interfaces with flare systems.
• Operational requirements: start-up, shutdown, pilot maintenance, purge and safe operating practices.
• Inspection, testing and maintenance recommendations for reliable and safe flare performance.
• Data-sheet formats and information exchange for design and procurement (aligned with industry practice and API 537 where specified).

Typical use and users

Used by process, mechanical and safety engineers, flare system designers, plant operators, maintenance and reliability engineers, procurement and inspection teams, consulting firms, and regulatory or permitting authorities involved in refinery, petrochemical and gas-processing facilities. It is referenced during new design, retrofit and performance-evaluation projects for flare systems.

Related standards

Notable related documents include API 537 (Flare System Monitoring/Details) — ISO 25457:2023 is explicitly published as a supplement to API 537 (3rd edition, 2017) in specified areas. The standard also follows the work program of ISO/TC 67/SC 6 and replaces the withdrawn ISO 25457:2008. National adoptions (EN/ISO, BS, ÖNORM, etc.) and tracked-change national versions may exist.

Keywords

flare system, flare tip, flare stack, combustion, pressure-relief, vapour-depressurizing, refinery, petrochemical, natural gas, API 537, maintenance, inspection, ISO/TC 67

FAQ

Q: What is this standard?

A: ISO 25457:2023 is an International Standard that specifies requirements and guidance for the selection, design, specification, operation and maintenance of flare systems and related combustion and mechanical components for oil and gas (refinery and petrochemical) service.

Q: What does it cover?

A: It covers mechanical details, combustion system design, interfaces with pressure-relieving and vapour-depressurizing systems, operational and maintenance practices, and data-sheet/specification guidance; it is intended primarily for onshore facilities with guidance for offshore use and is issued as a supplement to API 537 where indicated.

Q: Who typically uses it?

A: Process, mechanical and safety engineers, flare designers, plant operators, maintenance teams, procurement specialists, consultants and regulators working on refinery, petrochemical and gas-processing projects.

Q: Is it current or superseded?

A: ISO 25457:2023 is the current published edition (effective 13 October 2023) and supersedes the withdrawn ISO 25457:2008.

Q: Is it part of a series?

A: It is part of the ISO/TC 67 series of standards for oil, petrochemical and gas industries (work of ISO/TC 67/SC 6) addressing flare and pressure-relief systems; it also links to industry documents such as API 537 for certain requirements and practices.

Q: What are the key keywords?

A: Flare, flare tip, flare stack, combustion, pressure-relief, vapour-depressurization, refinery, petrochemical, natural gas, maintenance, API 537.