Overview
ISO 7076-3:2016 - Fire protection - Foam fire extinguishing systems - Part 3: Medium expansion foam equipment specifies requirements and test methods for medium expansion foam equipment used in fixed foam extinguishing systems for indoor and/or outdoor applications. The standard defines performance, materials, durability and testing criteria to ensure reliable operation with foam concentrates and foam solutions.
Key topics and technical requirements
- Scope and definition
- Covers medium expansion foam (expansion ratio 21 to 200).
- Materials and corrosion resistance
- Metal parts exposed to foam concentrate/solution must resist corrosion; moving parts must be corrosion-resistant (bronze given as a typical example).
- Elastomeric joint rings
- Minimum tensile strength, elongation and hardness criteria for silicone, fluoroelastomers and other rubbers (examples: silicone ≥ 3.4 MPa tensile; fluoroelastomers ≥ 6.9 MPa; others ≥ 8.3 MPa).
- Ageing and liquid‑exposure requirements (e.g., oven ageing and exposure tests specified).
- Plastics and reinforced resins
- Requirements for resistance to ageing and liquid exposure - retained tensile, elongation or impact strength ≥ 50% of original and no cracking.
- Mechanical strength and leak resistance
- Hydrostatic strength: withstand 4× maximum working pressure for 5 minutes (sample testing rules apply).
- Leak test: withstand 1.5× maximum working pressure for 5 minutes without leakage.
- Performance metrics
- Discharge coefficient (K factor) tolerance: ±5% of manufacturer’s stated value.
- Foam quality: expansion and drainage time must meet manufacturer-stated values when tested with recommended foam concentrate.
- Design, maintenance and marking
- Requirements for connections, removable parts for routine maintenance, correct re‑assembly design, marking and manufacturer instructions.
- Test methods
- Includes ageing, liquid exposure, pressurization, leak, K-factor measurement, expansion/drainage measurement, water flow, operational reliability, stress corrosion, salt-spray, light/water exposure, heat and fire resistance.
Applications and users
- Who uses it
- Foam equipment manufacturers, fire protection engineers, testing and certification labs, specifiers, procurement teams, and authorities having jurisdiction.
- Practical applications
- Design and qualification of fixed medium expansion foam systems for warehouses, process areas, fuel‑related hazards and other indoor/outdoor installations.
- Verifying material compatibility with foam concentrates, ensuring reliable discharge performance, and establishing maintenance and marking practices.
Related standards
- ISO 7076 series: Part 1 (proportioning), Part 2 (low expansion), Part 5 (fixed compressed air foam) and other parts in development.
- Normative references include ISO 7203-2 (foam concentrates), ISO 9227 (salt spray), ISO 7-1/228-1 (threads), ISO 188 (rubber ageing), among others.