A refinery has two product tanks in series; a 10,000 gallon tank in which blendstocks are combined to produce gasoline (a blend tank), followed by a 50,000 gallon tank which feeds directly to the rack. Customers pull product from the rack. There are no blend streams going into the 50,000 gallon tank. Can we just certify the 10,000 gallon tank for all the properties for a specific volume (batch), without actually sampling any product from the larger tank?
The refiner should certify the properties of each batch produced in the 10,000 gallon blend tank based on a sample of gasoline collected after all the blending components have been added and mixed. The volume of each batch would be the volume of gasoline that is transferred from the blend tank up to the point when additional blendstocks are added to the blend tank to begin the subsequent batch. No certification sampling and testing would be required of gasoline from the 50,000 gallon tank. (8/29/94)
This question and answer was posted at List of Reformulated Gasoline and Anti-Dumping Questions and Answers: July 1, 1994 through November 10, 1997 (pdf)