A knowledge of the water content of petroleum products is important in the refining, purchase, sale, and transfer of products.

The amount of water as determined by this test method (to the nearest 0.05 or 0.1 volume %, depending on the trap size used) may be used to correct the volume involved in the custody transfer of petroleum products and bituminous materials.

The allowable amount of water may be specified in contracts.

1.1 This test method covers the determination of water in the range from 0 to 25 % volume in petroleum products, tars, and other bituminous materials by the distillation method.

Note 1—Volatile water-soluble material, if present, may be measured as water.

1.2 The specific products considered during the development of this test method are listed in Table 1. For bituminous emulsions refer to Test Method D244. For crude oils, refer to Test Method D4006 (API MPMS Chapter 10.2).

Note 2—With some types of oil, satisfactory results may be obtained from Test Method D1796 (API MPMS Chapter 10.6).

1.3 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.

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. For specific hazard statements, see Section 6.