This test method is intended for use in evaluating distillate fuel cleanliness in those applications that demand a high throughput per installed filter.

A change in filtration performance after storage or pretreatment can be indicative of changes in fuel condition.

Causes of poor filterability might include fuel degradation products, contaminants picked up during storage or transfer, or interaction of the fuel with the filter media. Any of these could correlate with orifice or filter system plugging, or both.

1.1 This test method covers three procedures for the determination of the filter blocking tendency (FBT) and filterability of middle distillate fuel oils and liquid fuels such as biodiesel and biodiesel blends. The 3 procedures and associated filter types, are applicable to fuels within the viscosity range of 1.3 to 6.0 mm²/s at 40C.

ASTM specification fuels falling within the scope of this test method are: Specifications D 396 Grades No 1 and 2; Specification D 975 Grades 1-D, low sulfur 1-D and 2-D; Specification D 2880 Grades 1-GT and 2-GT; Specification D 6751.

1.2 This test method is not applicable to fuels that contain free (undissolved) water (see ).

1.3 The values stated in SI Units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.