api defines custody transfer
metering, process measurement, flare. and stack gas measurement, district. heating, LNG measurement, and shale. gas measurement. Different flow tech-. nologies are used for these applications. But custody transfer is one of the most. important applications. Custody transfer occurs when the. possession of a fluid, such as oil, gas, water, or steam, changes hands from. one owner to another. The owner could, for example, be an oil or gas production. company, a pipeline company, or a util-. ity company.