Abstract: Swirl-vane separator is one of the key components of the gas-liquid separating part in steam generator to provide high quality steam to turbine. Liquid droplets or film is separated from gas mainly due to the different gas and liquid centrifugal forces and gravities. The gas liquid mixture goes to the separator, and liquid water is separated from the mixture gradually. Water drainage happens at the inlet, downcomer and slots due to the reversed liquid water. To get the drainage performance at these three regions, an airwater swirlvane separator test rig was developed. The riser diameter of the separator tested is 140 mm and the inclination angle of the swirlvane is 30°. The gas velocity ranges from 5 m/s to 13 m/s. The water fraction from three regions was obtained. It’s found that high fraction of water drainage is from the inlet and the downcomer. When the gas velocity is around 79 m/s, the fraction of water drainage from downcomer is significant. The slot plays significant role for the water drainage when gas velocity is high.