Abstract: A control system for a steam turbine is disclosed which is operative to protect the turbine from the effects of sudden changes in steam supply pressure, and in particular to protect the turbine from the effects of water induction such as occurs with a sudden drop in steam pressure supplied by a boiler. In a preferred embodiment, a signal is created which represents the time rate of change of steam supply pressure. This derivative signal is compared with a preselected threshold value to produce a pulse signal whose duty cycle is proportional to the amount by which the rate of change of pressure exceeds the preselected threshold value. The pulse signal causes a proportional pulsing of a motor adapted to reduce a turbine load limit and effect a closing of steam admission control valves to counteract the change in steam pressure and reduce the potential for passing wet steam to the turbine.