Steam turbine Parson is steam turbine which has working principle of reaction with axial flow. Steam turbine Parson is generally terraced for large capacity and low rotation. Steam expand both on the steering blade and motion blade so direct push on the blade in the axial direction.
Although conversion energy occur both on steering blade and motion blade, steam turbine produce tangential power only in motion blades. Furthermore steam turbine Parson can be called also as steam turbine semi reaction.