ASTM D5985-96e1

The pour point of a petroleum product is an index of the lowest temperature of its utility for certain applications. Flow characteristics, such as pour point, can be critical for the correct operation of lubricating systems, fuel systems, and pipeline operations.

Petroleum blending operations require precise measurement of the pour point.

This test method can determine the temperature of the test specimen with a resolution of 0.1°C at which either crystals have formed or viscosity increases sufficiently to impede movement of the petroleum product.

This test method yields a pour point in a format similar to Test Method D 97/IP15 when the 3°C interval results are reported.

Note 2—Since some users may wish to report their results in a format similar to Test Method D 97 (in 3°C intervals) the precisions were derived for the temperatures rounded to the 3°C intervals. For statements on bias relative to Test Method D 97, see 13.3.

This test method has better repeatability and comparable reproducibility relative to Test Method D 97 as measured in the 1992 interlaboratory program.⁵

1.1 This test method covers the determination of pour point of petroleum products by an automatic instrument that continuously rotates the test specimen against a suspended detection device during cooling of the test specimen.

1.2 This test method is designed to cover the range of temperatures from -57 to + 51°C; however, the range of temperatures included in the 1992 interlaboratory program only covered the temperature range of -39 to + 6°C (see 13.4).

1.3 This test method determines the no-flow point of petroleum products by detection of the crystal structure or viscosity increase, or both, in the sample that is sufficient to impede flow of the specimen.

1.4 This test method is not intended for use with crude oils.

Note 1—The applicability of this test method on residual fuel samples has not been verified. For further information on applicability, refer to .

1.5 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.

1.6 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.