The components in a gravity oil/water separator were divided into four types according to their function

which are energy exchanging (inlet)

flow stabilizing

coalescence strengthening and vortex preventing (outlet) components.Some typical geometry for each component was put forward and investigated experimentally with the PIV technique. As a result

a new geometry for the separator was developed. In order to compare the new model s performance with other separators such as C - E Natco s performax separator and Henan oilfields HNS - Ⅱ separator

their hydraulic behaivor and separation performance were investigated by using resident time distribution and water in oil analysis techniques. All the work show that the new geometry proposed in the study is the best one both in hydraulic behavior and in separation performance.