1. n. [Production Facilities]

The amount of time a liquid stays in a vessel. The retention time assures that equilibrium between the liquid and gas has been reached at separator pressure. The retention time in a separator is determined by dividing the liquid volume inside the vessel by the liquid flow rate. The retention time usually varies between 30 seconds and 3 minutes. If a foaming crude is present, the retention time could be increased by four times its normal values.

Synonyms: residence time