Woodward

Woodward Industrial Turbine Fuel Control Valves

    Water Control Valves for Gas Turbines

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    EWMV-Electric Water Metering Valve

    Woodward’s EWMV (Electric Water Metering Valve) controls water flow to an industrial gas turbine combustion system for reduction of NOX emissions. Our valve and all-electric actuator are integrated for precise control under all operating conditions. The valve section of the EWMV consists of a flow controller and a throttling pressure regulator. The regulator maintains a constant differential pressure across the control plug and seat. Plugs are contoured to provide an equal percent flow characteristic. Since water can result in cavitation problems, the throttling components are made from specialty ceramic materials.

    The EWMV is supplied with an integral all-electric actuator that uses a brushless dc motor to drive the valve mechanism. Within the motor assembly is a position resolver that acts as the primary motor commutation and actuator/valve position feedback device. This position signal is used by the external Woodward DVP (Digital Valve Positioner) as feedback in order to properly position the EWMV. A second resolver is attached to the valve stem and acts as a backup to the primary motor resolver. The actuator portion of the EWMV Water Control Valve uses a soft stop spring that prevents the actuator from slamming into the minimum stop position in cases of fault detection.