Cloud and Pour Point
Cloud Point and Pour Point
refers to the temperature below which wax in diesel or biowax, forms a cloudy appearance in biodiesels. The presence of solidified waxes thickens the oil and clogs fuel filters and injectors in engines. The wax also accumulates on cold surfaces and forms an emulsion with water (producing, for example, pipeline or heat exchanger fouling). Therefore, cloud point indicates the tendency of the oil to plug small orifices or filters at cold operating temperatures. ASTM D2500, is the Standard Manual Test Method for measuring Cloud Point of Petroleum.
of a liquid is the temperature at which it becomes semi-solid and loses its flow characteristics. In crude oil, a high pour point is generally associated with a high paraffin content, typically found in crude deriving from a larger proportion of plant material. ASTM D97 is the standard test method for measuring the pour point of petroleum. ASTM D5853 is the standard test method for measuring pour point of crude oils and ASTM DD6892 is the standard automatic test method for measuring pour point of crude oils.