Overview
EN ISO 11114-3:2010 specifies an autogenous ignition test method to determine the autogenous ignition temperature of non‑metallic materials in a pressurized oxygen atmosphere. The measured ignition temperature is used as a criterion to rank materials for oxygen compatibility and to assist with safe selection of materials for gas cylinders, valves and accessories that come into contact with gaseous oxygen.
Key topics and technical requirements
- Test principle: A small amount of test material is heated in a sealed reaction chamber filled with pressurized oxygen. Continuous recordings of temperature and pressure identify the point of sudden increase (autogenous ignition temperature).
- Sample preparation: Liquids or finely divided solids; typical sample mass range is 0.06 g to 0.5 g (adjusted for chamber volume).
- Apparatus requirements:
- Reaction chamber inside an oven with controlled heating rate (typical heating rates recommended between 5 °C/min and 20 °C/min; higher rates can affect results).
- Thermocouple located close to the sample with accuracy ±2 °C (25–500 °C).
- Pressure transducer with ~1% full‑scale accuracy.
- Equipment designed to withstand possible violent internal reactions.
- Test conditions:
- Oxygen purity of at least 99.5% is required (hydrocarbon content is restricted by the standard).
- Oxygen pressure affects ignition temperature (higher pressure generally lowers the ignition temperature); for material ranking a starting pressure of 100 bar is recommended when determining minimum ignition temperature.
- Maximum test temperature is typically 500 °C.
- Results and reporting: The autogenous ignition temperature is taken from the temperature/pressure vs. time trace; magnitudes of temperature (ΔT) and pressure (Δp) rises characterize reaction violence. Test records follow the annexed sheet.
Applications and who uses it
- Material selection and safety assessment for transportable gas cylinders, cylinder valves, and oxygen service components.
- Manufacturers and type‑testing laboratories performing oxygen compatibility testing for cylinder valves (e.g., to satisfy requirements in ISO 10297).
- Safety engineers, R&D teams, and standards compliance officers in industries using high‑pressure oxygen (medical, industrial gas supply, aerospace, welding and cutting).
- Useful for ranking non‑metallic polymers, elastomers and composites to reduce fire/explosion risks in oxygen service.
Related standards
- EN/ISO 11114 series (Parts 1–4): broader material compatibility guidance (metallic and non‑metallic).
- ISO 10297: requirements for cylinder valves for highly oxidizing gases.
- Other oxygen‑compatibility methods referenced in the standard: ISO 4589‑3 (oxygen index), ISO 21010 (adiabatic compression/heat of combustion).
Keywords: EN ISO 11114-3:2010, autogenous ignition test, oxygen compatibility, gas cylinders, non‑metallic materials, oxygen atmosphere, ignition temperature, valve materials.