ISO 28300:2008

Overview

ISO 28300:2008 - "Petroleum, petrochemical and natural gas industries - Venting of atmospheric and low‑pressure storage tanks" defines requirements for normal and emergency vapour venting of aboveground liquid petroleum and petroleum‑product storage tanks and refrigerated tanks (aboveground and underground) designed as atmospheric or low‑pressure tanks. It covers causes of overpressure and vacuum, methods to determine venting requirements, selection and installation of venting devices, and testing and marking of relief devices. The standard is aimed primarily at petroleum products but can be applied to other liquids using sound engineering judgment. Note: external floating‑roof tanks are excluded.

Key topics and technical requirements

• Causes of overpressure and vacuum - includes liquid transfer, tank breathing from weather changes, fire exposure and equipment failures (e.g., inert‑gas purge failures, pressure transfer vapour breakthrough).
• Determination of venting requirements - methods for sizing vents to handle normal (operational/thermal breathing) and emergency (ruptured coils, fire) scenarios.
• Means of venting and device selection - guidance on types of relief devices (PV valves, pressure‑relief devices), set pressures, rated relieving capacity and installation considerations.
• Refrigerated vs non‑refrigerated tanks - separate considerations for refrigerated storage (thermal contraction/expansion and specific relief‑device specifications).
• Testing, documentation and marking - test methods for rated capacity, production testing, and manufacturer documentation/marking requirements.
• Informative annexes - provide alternative calculation methods, sizing equation bases, device characteristics, and guidance on inert‑gas blanketing and flashback protection.

Practical applications and who uses it

ISO 28300:2008 is essential for:

• Tank designers and mechanical engineers sizing vents and specifying relief devices.
• Operations and maintenance teams implementing safe venting practices and testing regimes.
• Safety and process engineers performing risk assessments for overpressure/vacuum events and fire scenarios.
• Relief device manufacturers and test laboratories for capacity testing, marking and documentation.
• Inspectors and regulators ensuring compliance with venting requirements for petroleum storage facilities.

Practical benefits include safer tank operation, reduced risk of structural failure, improved compliance with international best practice, and guidance for integrating venting with inerting, vapour recovery and hazardous‑area controls.

Related standards

Normative references cited in ISO 28300:2008 include:

• ISO 4126‑4 (pilot‑operated safety valves)
• ISO 16852 (flame arresters)
• ISO 23251 (pressure‑relieving and depressuring systems)
• IEC 60079‑10 (hazardous area classification)
• DIN 4119 (above‑ground cylindrical flat‑bottom tanks)

Keywords: ISO 28300:2008, venting, storage tanks, petroleum, petrochemical, natural gas, relief devices, PV valve, normal venting, emergency venting, tank breathing, refrigerated tanks.