Overview
ISO 20783-2:2003 - "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 the HFB family (including HFB.LT for low‑temperature use). The document defines three complementary test methods for storage stability at controlled temperatures and sets out required apparatus, reagents, sampling, calculation and reporting rules.
Key topics and technical requirements
- Scope & applicability
- Tests are for HFB fluids as defined in ISO 6743‑4.
- Method A: storage at ambient temperature (20 ± 2 °C); applicable to HFB and HFB.LT.
- Method B: storage at medium temperature (70 ± 2 °C); applicable to HFB and HFB.LT.
- Method C: storage at low temperature (−10 ± 2 °C); applicable to HFB.LT only.
- Test structure
- Standardized sample volumes and containers (e.g., 500 ml graduated cylinders with a 50 ml water layer and ~450 ml emulsion for Method A).
- Defined sampling levels (for Method A: 425 ml and 125 ml) and use of 50 ml pipettes to obtain sub‑samples.
- Determination of water content by distillation according to ISO 3733 (apparent water content noted if water‑soluble liquids distil over).
- Measurements of surface oil layer and accumulated free water after storage (Example: Method A storage duration given as 1 000 h).
- Supporting requirements
- Specified reagents (laboratory water to ISO 3696; petroleum spirit), glassware (ISO 648 pipettes), and sampling procedures (ISO 3170).
- Sections covering procedure, calculation (change in water content, mean values), precision and test reporting.
- Safety note
- The standard includes a warning that hazardous materials and operations may be involved and that users must apply appropriate safety and regulatory controls.
Practical applications and users
- Quality control and batch acceptance testing for manufacturers of fire‑resistant hydraulic fluids (HFB / HFB.LT).
- Product development and stability screening during formulation of emulsified, fire‑resistant fluids.
- Independent testing laboratories performing emulsion stability, shelf‑life and compatibility assessments.
- Specifiers, procurement and safety engineers who need validated stability data for equipment operating in ambient, medium‑ or low‑temperature environments.
- Regulatory and certification bodies requiring standardized test evidence for product classification.
Related standards
- ISO 6743‑4 - classification of hydraulic fluids (defines HFB categories)
- ISO 3733 - determination of water by distillation (referenced for water content analysis)
- ISO 3170 - manual sampling of petroleum liquids
- ISO 3696, ISO 648 - laboratory water and pipette specifications
- ISO 20783‑1 - Part 1: HFAE fluids (companion document for other fluid categories)
Keywords: ISO 20783-2:2003, emulsion stability testing, fire‑resistant fluids, HFB, HFB.LT, hydraulic fluids, water content, ISO 3733, laboratory test methods.