Overview
EN 15004-2:2025 - Fixed firefighting systems - Gas extinguishing systems - Part 2: Physical properties and system design of gas extinguishing systems for FK-5-1-12 (ISO 14520-5:2024, modified) is a CEN standard that defines the physical characteristics, specification, usage and safety requirements for FK-5-1-12 total‑flooding gaseous fire‑extinguishing systems. Applicable systems are those using nitrogen propellant and operating at nominal pressures of 25 bar, 34.5 bar, 42 bar, 50 bar and 70 bar.
Key topics and technical requirements
- Extinguishant specification: Minimum purity 99.0 % mol/mol, limits on acidity, water content, non‑volatile residue and dimers (kinetic and thermodynamic) are defined.
- Physical properties: Chemical name dodecafluoro-2‑methylpentan-3‑one (CF3CF2C(O)CF(CF3)2). Tables provide molecular mass, boiling/freezing/critical points, vapour and liquid densities, heat of vaporization and specific volume data used for design calculations.
- Fill density & design concentration: Methodology and tables for calculating agent mass per unit volume (m/V) at different temperatures and target concentrations (e.g., 3–10 % by volume). Reference extinguishing and minimum design concentrations are given for representative fuels (heptane, Surface Class A materials). Example: heptane cup‑burner extinguishment 4.5 % v/v, minimum design 5.9 % v/v.
- System design considerations: Requirements for determining extinguishant quantity, superpressurization levels, and alternative fill/superpressure scenarios (including new provisions for 50 bar and 70 bar containers).
- Safety of personnel: Mandatory assessment of hazards from the extinguishant, combustion products and extinguishant breakdown products; toxicological data and minimum safety provisions reference EN 15004-1:2024.
- Environmental properties: Environmental information and guidance on selection/usage are included.
Practical applications
- Design and verification of total‑flooding FK-5-1-12 systems for data centers, telecommunication facilities, museums, archives, engine rooms and other enclosed hazards requiring electrically non‑conductive gaseous suppression.
- Determining correct agent quantities, storage pressures and discharge parameters for reliable extinguishment while addressing safety and environmental constraints.
- Supporting procurement specifications, acceptance testing, and risk assessments for fixed gas extinguishing installations.
Who should use this standard
- Fire protection engineers and system designers
- Installation and maintenance contractors
- Facility owners and asset managers (data centers, archives, industrial plants)
- Regulatory authorities, insurers and safety auditors
Related standards
Keywords: EN 15004-2:2025, FK-5-1-12, gas extinguishing systems, fixed firefighting systems, design concentration, fill density, nitrogen propellant, CEN, ISO 14520-5:2024.
