ISO 14520-15:2015

Overview

ISO 14520-15:2015 defines physical properties and system design requirements for gaseous fire‑extinguishing systems using the IG‑541 extinguishant. IG‑541 is an inert gas mixture (nominally 52% nitrogen, 40% argon, 8% carbon dioxide) that extinguishes fires mainly by reducing oxygen concentration. This part of ISO 14520 covers specification, usage, safety and system design data for systems filled at nominal pressures of 150 bar, 200 bar, and 300 bar (at 15 °C). It supports design of total‑flooding systems and provides the quantitative data needed to size agents and storage containers.

Key Topics

• Extinguishant composition and purity: IG‑541 component ranges and purity/moisture/oxygen limits for argon, nitrogen and CO2 are specified; carbon dioxide is the primary analyte for batch verification.
• Physical properties: Molecular mass (~34.0), boiling and freezing points, specific vapour volumes and related thermodynamic data needed for storage and discharge calculations are provided.
• Design concentrations and agent quantities: Tables give required IG‑541 volumes (m3 agent per m3 protected volume) and design concentrations for fuels (e.g., heptane, Class A surfaces, various Class B fuels). Example: heptane minimum design concentration ~43.9% by volume.
• System pressures and container data: Nominal filling pressures at 15 °C and maximum working pressures at 50 °C are listed for 150, 200, 300 bar systems (e.g., 150 bar fill, max 175 bar at 50 °C).
• Safety of personnel: Physiological information (NOAEL ≈ 43% IG‑541; LOAEL ≈ 52% - corresponding to approx. 12% and 10% oxygen) and guidance on hazards from oxygen depletion and combustion products are included.
• Usage scope: Guidance for total‑flooding installations and inerting applications, and reference tables for extinguishment and inerting concentrations for many fuels.

Applications

ISO 14520-15:2015 is used by:

• Fire protection engineers and system designers for sizing IG‑541 total‑flood systems and selecting storage pressure options.
• Specifiers and consultants preparing tender and compliance documentation for data centers, archives, control rooms, industrial enclosures and other spaces where clean‑agent total flooding is required.
• Manufacturers and installers of gaseous fire suppression systems to verify container fill pressures, mixture specifications and discharge quantities.
• Safety managers and authorities having jurisdiction (AHJs) evaluating personnel safety, evacuation procedures and concentration limits.

Practical tasks supported: calculating required agent mass/volume per protected volume, selecting appropriate storage pressure (150/200/300 bar), checking purity and component tolerances, and applying design concentrations for specific fuel hazards.

Related Standards

• ISO 14520‑1:2006 - General requirements for gaseous fire‑extinguishing systems.
• Other parts of ISO 14520 that cover alternative extinguishants (e.g., IG‑55, IG‑100, HFC and FK blends) for cross‑reference when comparing agent properties and system design options.