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Steam valves found on most steam
turbines employ hydraulic actuators of the Low Pressure
or High Pressure type. One of the key elements in upgrading
steam turbine controls is the interface to existing
steam valves. We provide complete actuator system
designs, compatible with the control system, and turnkey
installation.
Generally, our control upgrades interface
directly to HP hydraulic systems, with minimal modifications
required on servos and position feedback devices. In
some cases, existing HP hydraulic systems may be upgraded
to improve valve performance.
Pilot actuators
We provide a range of Pilot actuators for interface
to existing MHC systems common on older GE and Westinghouse
design units.
Hydraulic servomotors
Many European design turbines, including older ABB
and Alstom units, employ low pressure hydraulic servomotors for valve controll. We offer a range
of I/P (current to pressure) units for control
of
these type of servomotor systems. This is a relatively
inexpensive
way to upgrade, since the existing low pressure hydraulic
servomotors need not be changed.
HP
hydraulic upgrades
HP actuators are now common on most new turbines,
and many upgrades involve upgrading to HP actuator
systems
to provides better valve position dynamics and
control accuracy. This involves replacing the
existing LP
hydraulic actuators and providing a new HP hydraulic
actuators and hydraulic power unit (HPU).
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