The VariStroke Actuator offers the following benefits to the user in comparison to

other electro-hydraulic actuators:

Dirt Tolerance—The VariStroke-I 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-I actuator is designed to operate reliably within such challenging

applications. Its corrosion-resistant materials, single moving rotary valve, 222 N

(50 lbf) of chip shear force, and self-cleaning port design allow it to operate in

such applications without experiencing undesirable sticking or dragging.