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The 3151A Water Valve/EML100 Actuator assembly is used as part of a gas-turbine nitrous oxide emission-reduction system. The unit meters water into an industrial gas turbine’s combustion chamber, lowering combustion temperature. This assembly is designed to be used with the Woodward EM Digital Driver or Woodward 24 V DVP.
3151A Water Valve
The 3151A Water Valve is intended for use with high-pressure centrifugal-type pumps and provides metered bypass flow for pump-stability and heat-balance considerations.
The water valve is primarily constructed of stainless steel. A replaceable, hardened, stainless-steel sleeve is located in the drain flange area of the valve housing, and protects the housing from cavitation damage. The sleeve can be rotated in onequarter turn increments, or it can be replaced, to extend valve life when used in severe conditions.
Ceramic is used on metering valve and regulator valve parts to prevent galling and to resist erosion in an area subjected to high-velocity water streams.
These design features make the 3151A Water Valve highly resistant to erosion, corrosion, and cavitation.
The Water Valve is designed to meter up to 250 L/min (66 US gal/min) with input pressures from 2413 to 10 342 kPa (350 to 1500 psig). The minimum flow is 3.8 L/min (1 US gal/min), dependent on inlet pressure.
Flow accuracy is 5.0% of point or 0.5% of maximum flow, whichever value is greater.
Standard seal material allows operation with water temperatures up to 66 °C (150 °F). The minimum operating temperature is 0 °C (32 °F).
The EML100 Actuator consists of a high performance brushless servomotor and a precision planetary gearbox with two resolver type shaft position sensors. The use of a high efficiency gearbox facilitates high servo system bandwidth. One resolver provides motor rotor position feedback and the other resolver(s) provides accurate output shaft position feedback. The gear train has a slip clutch to allow full speed impact into the rigid mechanical stops without damage.
The EM Driver controls the position of the EML100 actuator and water valve. Demand to the EM Driver is provided by a separate turbine control. The control may be calibrated so that the water valve closely follows the fuel-flow schedule to prevent unwanted water insertion during turbine load swings.
Product Specification 40187