Overview
ISO 15029-1:1999 specifies a laboratory method for assessing the spray ignition characteristics of fire-resistant fluids by measuring spray flame persistence using a hollow‑cone nozzle. It is intended for evaluating the unsupported burning time of a pressurized, atomized spray after removal of an igniting flame. The procedure is commonly used in classification, quality control and regulatory compliance related to fire‑resistant hydraulic fluids.
Key topics and technical requirements
- Test principle: Heat and pressurize the fluid, atomize through an 80° hollow‑cone nozzle, ignite successive points along the spray with an oxy‑acetylene blowpipe, withdraw the igniting flame and measure the time until the spray extinguishes. The reported result is the maximum unsupported burning time (flame persistence) to 0.1 s.
- Critical parameters
- Pressure: nitrogen supply at 7 MPa ± 0.3 MPa for atomization.
- Nozzle: 80° hollow‑cone type rated ~9.5 l/h at 700 kPa.
- Test temperature: water‑based/emulsion fluids - 65 °C ± 5 °C; other fluids - 85 °C ± 5 °C.
- Air flow: 0.2–0.3 m/s in direction of the jet during the test.
- Ignition: oxy‑acetylene blowpipe with specified gas pressures (oxygen/acetylene per blowpipe design).
- Measurement: timing device accurate to 0.1 s; test repeated at not less than five positions along spray length.
- Apparatus essentials: pressure vessel (~1.5 L), heating device (1 200–1 800 W), temperature sensors (±0.2 °C), appropriate pressure gauges and relief/control valves.
- Sample handling: sampling per ISO 3170, check for sediment or free water, store 0–30 °C before test.
- Result interpretation: report the highest persistence time recorded; no statistical precision established because the method is used as a go/no‑go test (an absolute maximum of 30 s is cited as a threshold for fire‑resistance).
- Safety note: contains hazardous operations - users must establish appropriate safety practices.
Applications and users
- Manufacturers and formulators of fire‑resistant hydraulic fluids conducting product development and batch QC.
- Independent test laboratories and certification bodies performing conformity and regulatory testing.
- Design and safety engineers selecting fluids for hydraulic systems in fire‑prone or safety‑critical applications (mining, industrial hydraulics).
- Regulatory authorities referencing standardized test methods for fire resistance classification.
Related standards
- ISO 3170 - Petroleum liquids: manual sampling (referenced normative).
- ISO 6743-4, ISO 7745, ISO 12922 - standards and guidance for hydraulic fluid classification, specification and use.
- ISO 14935 - wick flame persistence of fire‑resistant fluids.
- ISO 15029 series - Parts 2 and 3 cover alternative spray ignition assessment methods.
Keywords: ISO 15029-1, spray flame persistence, hollow-cone nozzle method, fire-resistant fluids, hydraulic fluid testing, spray ignition test, petroleum standards.