API MPMS 3.3:1996 (R2017)

This standard provides guidance on the installation, calibration, and verification of automatic tank gauges (ATGs) used in custody transfer for measuring the level of liquid hydrocarbons having a Reid vapor pressure of 15 psi (103 kilopascals) or greater, stored in stationary, pressurized storage tanks. The standard also provides guidance on the requirements for data collection, transmission, and receiving. This standard is not applicable to the following: a. Conversion of tank level to liquid volume. b. Measurement of free water or sediment lying under the liquid hydrocarbon. c. Measurement of temperature, density, or sediment and water (S & W). These measurements are discussed in the API Manual of Petroleum Measurement Standards (MPMS), Chapters 7, 9, and 10. d. Sampling for determination of the properties of the liquid hydrocarbon. This is discussed in API MPMS Chapter 8. e. Detection of tank leaks. f. ATGs used for inventory control and plant operations. Note: Converting net vapor space volumes to equivalent liquid volumes or mass is described in API MPMS Chapter 12. (The section covering calculation of vapor to liquid equivalent was in preparation at the time this standard was written.) This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems 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.