ASTM D4539 Test Method for Filterability of Diesel Fuels by Low-Temperature Flow Test (LTFT)
5. Apparatus
5.1 Glass Specimen Vessels, several 300-mL, clear, heat resistant, wide-mouthed glass bottles having markings indicating 200 mL +/- 10 mL and 50–60 mm ID or clear, heat resistant, tall form beakers with no pour spouts and equivalent dimensions.
5.2 Glass Receiver Vessels, clear, heat resistant, glass containers graduated through 180 mL in 10 mL +/- 2 mL increments.
5.3 Filtering Assembly (see Fig. 1), including a storage lid or some other form of cover, glass tubing, flexible fuel resistant tubing, pinch clamp and rubber stopper, or other means to provide a vacuum seal.
5.4 Filter, as shown in detail in Fig. 2, for each sample container (300-mL beaker). 304SS sintered screen is a twill Dutch weave mesh with a nominal filtration rating of 17 µm. The mesh is 65 wires/cm (165 wires/in.) X 303/315 wires/cm (770/800 wires/in.). The wire strands have diameters of 0.0071 cm (0.0028 in.) and 0.0046 cm (0.0018 in.), respectively. The nominal filtration rating indicates a 98 % removal by mass weight of all particles equal to or greater than 17 µm.
5.5 Programmable Cooling System, capable of cooling multiple specimens to the desired temperature at a mean rate of 1.0°C per hour between + 10°C and -30°C. Absolute deviation of any single temperature point along the prescribed ramp function must not exceed 0.5°C in any specimen. The system's size and shape are optional. Either liquid or air baths are acceptable.
5.6 Stop Watch or Electric Timer, capable of measuring tenths of a second.
5.7 Vacuum System, capable of maintaining a constant vacuum of 20.0 kPa +/- 0.2 kPa (150 +/- 1.5 mm Hg) (Warning - Mercury is a poison. See A2.4) below atmospheric pressure at the receiver for the duration of each determination.
5.8 Thermometers, total immersion type, having a range from -80 to + 20°C, and conforming to the requirements for Thermometer 114C for air baths or Thermometer 5C for liquid baths as prescribed in Specification E 1.
6. Reagents
6.1 Jet A Aviation Turbine Fuel - As specified in Specification D1655, kerosene, as specified in Specification D3699, Grade No. 1 (or Grade Low Sulfur No. 1), as specified in Specification D975, or equivalent liquid that will not separate at temperatures down to -30°C.
