Overview
EN ISO 20783-2:2003 (CEN) - Petroleum and related products - Determination of emulsion stability of fire‑resistant fluids - Part 2: Fluids in category HFB - specifies laboratory test methods to assess the emulsion stability of fire‑resistant hydraulic fluids in category HFB (including HFB.LT for low‑temperature applications) as defined in ISO 6743‑4. The standard defines three methods to evaluate how emulsions behave during storage at different temperatures: ambient, medium and low.
Key topics and technical requirements
- Scope and applicability
- Applies to HFB fluids; HFB.LT fluids are covered by Methods A and B and exclusively by Method C.
- Three test methods
- Method A (ambient storage): test at (20 ± 2) °C. A graduated cylinder is prepared with 450 ml of emulsion above a 50 ml water layer and stored for 1 000 h; subsequent sampling and water‑content analysis assess stability.
- Method B (medium temperature): test at (70 ± 2) °C to determine stability under elevated storage temperature.
- Method C (low temperature): test at (−10 ± 2) °C, applicable only to HFB.LT fluids for low‑temperature performance.
- Measurements and endpoints
- Initial and post‑storage water content (volume fraction) determined by distillation in accordance with ISO 3733 (apparent water content noted if water‑soluble components distil).
- Measurement of surface oil layer volume and accumulated free water after storage.
- Sampling technique: use of 50 ml pipettes and 500 ml measuring cylinders; representative sample volumes (minimums specified).
- Precision and reporting requirements for test results (including water content to nearest 0.2% where applicable).
- Apparatus and reagents
- Standard laboratory glassware (500 ml cylinders, 50 ml pipettes), petroleum spirit for rinsing, laboratory water meeting ISO 3696.
Applications and users
- Useful for:
- Petroleum and hydraulic fluid manufacturers performing quality control and product development.
- Laboratory analysts validating emulsion stability for fire‑resistant hydraulic fluids.
- End‑users (industrial hydraulics, power plants, heavy machinery) verifying fluid storage performance and fire safety compliance.
- Regulatory bodies and procurement teams specifying fire‑resistant fluids.
- Practical benefits:
- Predicts phase separation, water release and loss of protective properties after storage at service or storage temperatures.
- Supports product specification, shelf‑life assessment and failure investigation.
Related standards
Keywords: EN ISO 20783-2, emulsion stability, fire-resistant fluids, HFB, HFB.LT, petroleum standard, emulsion testing, water content, ISO 20783-2:2003.
