API MPMS CH 19.1

Description

Contains methodologies for estimating the total evaporative losses of hydrocarbons from fixed-roof tanks. The methodologies provide loss estimates for general equipment types based on laboratory, test-tank and field-tank data. Types of fixed-roof tanks and roof fittings described are for information only. The equations estimate average annual losses from uninsulated fixed-roof tanks for various liquid stocks, stock vapor pressures, tank sizes, meteorological conditions, and operating conditions. The following special cases are addressed: a. Horizontal tanks. b. Higher volatility stocks (true vapor pressure greater than 0.1 psia). c. Vent settings higher than 0.03 pounds (0.5 oz) per square inch. The estimation may be improved by using detailed field information, including climatic data and operational data for the appropriate time period. The equations are not intended to be used in the following applications: a. To estimate losses from unstable or boiling stocks or from petroleum liq