A drain system (10) for connection to a steam turbine (14). The drain system comprises a main drain line (20) providing a main flow path and a bypass drain line (28) providing a bypass flow path parallel to the main flow path. The main drain line and the bypass drain line are external to the steam turbine. The drain system further comprises a drain orifice assembly (22) within the main drain line, with the drain orifice assembly accessible during operation of the steam turbine. The main drain line and the bypass drain line are connected to a drain path (24) for carrying condensate and contaminants from the steam turbine.