The VariStroke-II Actuator offers the following benefits to the user in comparison to other electro-

hydraulic actuators:

Dirt Tolerance

The VariStroke-II actuator is specifically designed for steam turbine applications where turbine lube oil is

also used to power the hydraulic turbine control valve actuator(s). Steam turbine applications can be

extremely challenging for hydraulic control valve actuators as dirt, metal shavings, water, and other

contaminants (Babbitt, ammonia, etc.) are common in such oil systems. Also due to the high

temperatures at which steam turbines operate, turbine oil breakdown is common, resulting in the creation

of a sludge-type substance and the varnishing of internal system components. However, the VariStroke-II

actuator is designed to operate reliably within such challenging applications. Its corrosion-resistant

materials, single moving rotary valve, 610 N (137 lbf) of chip shear force, and self-cleaning port design

allow it to operate in such applications without experiencing undesirable sticking or dragging.