The ASTM D6751 Cold Soak Test
Cold Soak Filtration Test
• Part of ASTM D6751, quality standard for biodiesel fuels. Measures the diesel’s ability to clog fuel filters after being subjected to cold temperatures
• Performance based test, where results are reported in seconds (The lower the number, the faster the fuel flowed during the test)
• Every biodiesel producer and blender must pass this (and other) tests after October 1st, 2009
Test Overview – ASTM D 7501 – 09 Cold Soak
300mL of test fuel is chilled to 40F for 16hrs
• After 16hrs, it is allowed to come to room temperature on its own (no heat, no energy)
• Fuel is put into funnel and pulled through a 0.7? (micron) glass fiber patch with stainless steel support pulled by a vacuum and the pressure shall be between71.1 and 84.7 kPa (21 and 25 in. of Hg) below atmospheric.
• The amount of time it takes to empty the funnel (in seconds) is recorded
• Currently, Less than 360 sec. is required to pass
• Less than 200 sec. is recommended for -10° C or less climates.
ASTM D 7501 – 09 vessel
Read more about all of the other ASTM Tests for Biodiesel here: