3151A Water Valve and TM Actuator for Gas Turbine Water Injection Systems


The 3151A Water Valve/TM-40LP Actuator assembly is used as part of a gas turbine nitrous oxide emission-reduction system. The assembly meters water into an industrial gas turbine's combustion chamber, lowering combustion temperature.


In normal operation, Woodward's electronic control positions the water valve to closely follow fuel-flow schedule. This positioning accuracy, together with the actuator's fast response time, prevents excess water injection into the turbine during transients.

The ability to quickly and accurately meter water over a large range, accomplishes two other very important tasks. It holds water costs to a minimum by metering only the exact amount of water required for effective emission control, and it prevents serious damage to the turbine resulting from excess water "wash-outs."

The assembly's efficient design provides an internal metered bypass flow for pump stability and efficient pump utilization.

The assembly is designed for use with supply pressures from 2413 to 10 342 kPa (350 to 1500 psi), and it can meter up to 250 L/min (66 gal[US]/min) of water, irrespective of supply pressure. The valve's flow accuracy is 5% of point or 0.5% of maximum flow—whichever value is greater.

Standard seal material allows operation with supply water temperature up to 66 °C (150 °F).