Overview
EN ISO 20783-1:2011 (CEN endorsement of ISO 20783-1:2011) specifies a laboratory test method to assess emulsion stability of fire-resistant fluids in category HFAE (as defined by ISO 6743‑4). The standard describes how to prepare emulsions using standard test waters with defined salt concentrations, age them under controlled temperatures, and evaluate oil separation and creaming visually. This method is applicable only to HFAE fluids and explicitly does not apply to HFAS fluids.
Key topics and technical requirements
- Scope and applicability: Emulsion stability test for HFAE fire‑resistant fluids (petroleum and related products).
- Principle: Prepare an emulsion with the manufacturer‑recommended proportion of emulsifying oil and a defined test water; store at specified temperature and duration; visually assess separation and creaming.
- Test waters: Use waters with clearly defined salt concentrations (see Annex A of the standard) to simulate compatibility conditions.
- Reagents & apparatus:
- Demineralized and potable water, acetone or isopropanol, dishwasher detergent.
- Hirschsohn flasks (150 or 200 ml) with cork bungs and an oven capable of (70 ± 2) °C or (50 ± 2) °C.
- Samples & sampling: Sample emulsifying oil per ISO 3170 procedures; prepare 1 L emulsion using the hardest compatible test water declared by the manufacturer.
- Test conditions (choose one):
- 70 ± 2 °C for 1 week, or
- 50 ± 2 °C for 3 weeks.
- Procedure highlights: Clean flasks, fill to mid-graduation, loosely bung during heating, tighten bungs at test temperature, then visually assess while hot.
- Assessment categories:
- Oil separation: 1A (none), 2A (traces), 3A (continuous film).
- Creaming: 1R (none), 2R (< 1 ml), 3R (> 1 ml).
- Express results as combined designation (e.g., 1A - 2R) based on at least two matching flask results; repeat if inconsistent.
- Precision & reporting: Precision not formally determined; test report must reference ISO 20783‑1 and provide product ID, water type, concentration, test conditions and results.
Applications and users
- Fire‑resistant fluid manufacturers: product development and compatibility declarations.
- Quality control laboratories: routine stability testing of HFAE emulsions.
- End‑users and purchasers: verifying supplier claims for hydraulic fluids and fire‑resistant systems.
- Regulators and certification bodies: assessing compliance with fire‑resistant fluid performance criteria.
Related standards
Keywords: emulsion stability, fire-resistant fluids, HFAE, ISO 20783-1, test method, petroleum products, emulsifying oil, oil separation, creaming.
