ASTM D6078 Standard Test Method for Evaluating Lubricity of Diesel Fuels
ASTM D6078 Standard Test Method for Evaluating Lubricity of Diesel Fuels by the Scuffing Load Ball-on-Cylinder Lubricity Evaluator (SLBOCLE)
6. Apparatus
6.1 Scuffing Load Ball-on-Cylinder Lubricity Evaluator (SLBOCLE):
6.1.1 The SLBOCLE consists of a fluid reservoir in which a cylinder rotates, a load arm to which a ball is attached, and a hanger to hang a load on the load arm. The SLBOCLE illustrated in Fig. 1 and Fig. 2 is identical to the ball-on-cylinder lubricity evaluator (BOCLE) specified in Test Method D5001, except for the modifications in 6.1.2 through 6.1.4. Complete operating conditions are listed in Table 1.
6.1.2 If a standard BOCLE machine is modified, a load cell is included to accurately measure tangential friction force with output to a recording device.
6.1.3 If a standard BOCLE machine is modified, a redesigned reservoir cover or splash guards is necessary to prevent loss of fluid from the joint between the reservoir cover and reservoir.
6.1.4 If standard BOCLE machine is modified, a heavy-duty pneumatic piston is required to facilitate the increased loads required in the SLBOCLE test.
6.1.5 Cylinder, the polished test ring and mandrel assembly. See Fig. 2.
6.1.6 Mandrel, a 10° tapered short cylindrical section used for holding test ring. See Fig. 2
6.2 Constant Temperature Bath Circulator, capable of maintaining the fluid sample at 25 +/- 1°C when circulating coolant through the base of the sample reservoir.
6.3 Cleaning Bath, ultrasonic seamless stainless steel tank with adequate capacity and a cleaning power of 40 W or greater.
6.4 One of the containers specified under Containers for Lubricity Testing in Practice D4306 shall be used to store and transport fuel samples.
6.5 Desiccator, containing a non-indicating drying agent, capable of storing test rings, balls, and hardware.
7. Reagents and Materials
7.1 Acetone, (Warning: Extremely flammable. Vapors may cause flash fire.) conforming to Specification D329.
7.2 Compressed Air, (Warning: Compressed gas under high pressure. Use with extreme caution in the presence of combustible material.) containing less than 0.1 ppmv hydrocarbons and 50 ppmv water.
7.3 Gloves, clean, lint-free, cotton, disposable.
7.4 Isooctane, (Warning: Extremely flammable. Harmful if inhaled. Vapors may cause flash fires.) conforming to Test Method D1016, 95 % purity minimum, 2,2,4-trimethylpentane.
7.5 Isopropyl Alcohol, (Warning: Flammable.) conforming to Specification D770.
7.6 Reference Fluids:
7.6.1 Fluid A - High lubricity reference18 Warning: Flammable.). Store in clean, borosilicate glass with an aluminum foil-lined insert cap. Store in a dark area.
7.6.2 Fluid B - Low lubricity reference18 (Warning: Flammable. Vapor harmful.)
7.7 Test Ball, chrome alloy steel, made from AISI standard steel No. E-52100, with a diameter of 12.7 mm, Grade 5 to 10 EP finish. The balls are described in ANSI Specification B3.12. The extra-polish finish is not described in that specification. The Rockwell hardness "C" scale (HRC) shall be 64 to 66, a closer limit than found in the ANSI requirement.
7.8 Test Ring, of SAE 8720 steel, having HRC number of 58 to 62 and a surface roughness between 0.04 and 0.15 µm after polishing as described in A1.1. The dimensions are given in Fig. 3.
7.9 Wiper, wiping tissue, light-duty, lint-free, hydrocarbon-free, disposable.
8. Sampling and Sample Containers
8.1 Unless otherwise specified, samples shall be taken by the procedure described in Practice D4057 or Practice D4177.
8.2 Because of the sensitivity of lubricity measurements to trace materials, sample containers shall be only fully epoxylined metal, amber borosilicate glass, or polytetrafluorethylene (PTFE), cleaned and rinsed thoroughly at least three times with the product to be sampled before use, as specified under Containers for Lubricity Testing in Practice D4306.
8.3 New sample containers are preferred, but if not available the Containers for Lubricity Testing section of Practice D4306 gives guidance on suitable cleaning procedures for each type of container.
