172-65169MA-08 (MC-COS Multi-control Valve) 28 May 2010
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Setting the Valve Coefficient
About the Valve Coefficient
1. Features of the
MC-COS
The MC-COS valve has a pressure self-adjustment function with the following
features:
1) Maintains the secondary steam pressure at a stable level even when the primary
steam pressure and secondary steam flow fluctuate.
2) Maintains the interrelationship between the secondary steam pressure and the
stroke position of the pressure adjustment screw determined by the drive section.
2. What is the valve coefficient?
The valve coefficient expresses the relationship between the secondary steam
pressure and the stroke position of the pressure adjustment screw on the MC-COS.
There are five different valve coefficients; labeled A through E. Valve coefficients are
derived by TLV for each valve through tests before shipment from the factory. They
are stamped on the valve coefficient nameplate label attached to the valve and a
removable label to be utilized for putting the valve coefficients into the controller.
Combining the
MC-COS
and the TLV SC-F70 or SP-F70 Controller
The SC-F70 digital indicator controller and SP-F70 programmable indicator controller
made by TLV use proprietary control algorithms designed to take full advantage of
MC-COS’s potential. Examples include MC-COS's high stability, resistance to
external disturbances and its precise response to setting changes. Combining the
MC-COS with these controllers provides a level of control not possible with other
conventional control valves and PID controllers.
Setting the Valve Coefficient
In order to fully utilize the MC-COS,
be sure to provide the SC-F70 or
SP-F70 controller with the MC-COS
valve coefficient.
Failure to do so will make AUTO
mode operation impossible and an
error message will be displayed on
the controller.
Valve Coefficient
Label
Valve Coefficient
Nameplate
