ISO 15364:2021

Overview

ISO 15364:2021 - "Ships and marine technology - Pressure‑vacuum valves for cargo tanks and devices to prevent the passage of flame into cargo tanks" - defines minimum performance, testing, design and in‑service requirements for pressure‑vacuum (PV) valves and flame‑preventing devices used on cargo tanks. The fourth edition expands the scope to explicitly include devices that prevent flame passage and incorporates the flame test procedures of ISO 16852:2016. The standard is intended to help manufacturers, shipyards and purchasers ensure equipment meets recognized safety and performance baselines for use in potentially explosive gas/vapour atmospheres on tankers and other cargo ships.

Key topics and technical requirements

• Scope & applicability: PV valves and flame‑preventing devices protecting cargo tanks subject to explosive gases/vapours or pressure/vacuum beyond tank design limits.
• Materials: Selection rules for pressure‑retaining components, corrosion resistance, prohibition of non‑metallic pressure parts (with limited exceptions), and bill‑of‑materials requirements (see Annex D/E guidance).
• Performance limits: Maximum leakage rates, capacity/flow requirements, and limits on valve leakage (Annex J).
• Type and production testing:
  • Flow and velocity tests (capacity determination, test apparatus, flow measurements).
  • Undamped oscillation tests (to ensure stable operation without piping‑induced oscillation).
  • Flame transmission tests per ISO 16852:2016 (for devices that prevent passage of flame).
  • Production control and inspections, third‑party witness/testing.
• Design & operational criteria: Valve opening characteristics (full opening, modulating, transition point, dual nozzle), spring and seat requirements, and guidance for non‑oscillating installation dimensions.
• Documentation, marking & QA: Verified drawings, verified flow charts, installation instructions, marking and quality assurance provisions (Clauses 10–13 and Annexes).

Applications and users

ISO 15364:2021 is used to:

• Specify and procure pressure‑vacuum valves and flame arresters for tankers, chemical carriers and barges.
• Develop manufacturer test programs, third‑party inspection protocols, and shipboard maintenance/operational testing procedures.
• Support naval architects, shipyards and system integrators in selecting appropriately rated PV devices and documenting suitability. Typical users:
• Valve and flame‑arrester manufacturers
• Shipowners, operators and marine technical managers
• Classification societies, flag states and regulatory bodies
• Third‑party inspection and testing laboratories
• Shipyards and naval architects

Note: Conformance to ISO 15364:2021 demonstrates that minimum requirements and essential information have been considered; it does not alone guarantee suitability for a specific installation.

Related standards and regulations

• ISO 16852:2016 - flame arrester test methods (incorporated)
• IMO SOLAS Chapter II‑2, Regulation 4 - minimum requirements for flame‑preventing devices
• IMO MSC/Circ.677 (and subsequent amendments MSC/Circ.1009, MSC/Circ.1324) - IMO guidance on design, testing and locating of flame‑preventing devices

Keywords: ISO 15364:2021, pressure‑vacuum valves, flame arrester, cargo tanks, tankers, marine safety, SOLAS, ISO 16852, valve testing, valve materials, tank venting.