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8402 - Gas Turbine Fuel Control Valve |
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Features● All Electric - Eliminates Need for a Hydraulic Actuation System ● Full Stroke Operating Speed of 250ms ● Durable Carbon Steel/Stainless Steel Con-struction ● Precise control of turbine allows a single valve to be used in applications where two valves were previously required ● Digital encoder provides position repeatability of ±0.05% of stroke ● Custom designed specifically for the con-trol of gas turbines (industrial or aero-derivative). Applications● Gas fuel control (metering) valve for industrial and aeroderivative gas turbines. OperationThe 8402 Fuel Valve System is a balanced rotary valve with an electric stepper-motor actuator. Position feed-back is provided by a 12 bit absolute digital encoder coupled to the drive mechanism. The valve has a 200:1 turn down ratio and will fully stroke (open to closed) in 250 milliseconds. The precise resolution provided by the digital encoder and digital stepper motor drive will allow a single 8402 to control flow over a wide range of turbine operation from light-off to full power. Position repeatabil-ity for the system is ±0.05% of full stroke. Combining the efficiency and accuracy of the Model 8402 with the durability of protection of AMOT's Model 4420 fuel shutoff valve AMOT provides a reliable, cost effec-tive control and shutoff system for any turbomachinery application. The actuator enclosure is designed for use in hazardous environments, and has been certified by CSA(Class 1 Division 1, groups C & D, explosion-proof). Electronic Control System The 8402 is controlled by a high-speed microprocessor in a separate enclosure. The controller receives a 4-20 mA setpoint signal and converts this into a 12 bit digital value to drive the stepper-motor/digital encoder loop. The stepper-motor driver is capable of 1667 discrete steps across the 60° of full stroke actuation. Position feedback is provided by a 12 bit absolute digital encoder providing a resolution of 0.022° of position per bit. The encoder signal/value position is compared to the set point value to verify position accuracy. An error signal is calculated by comparing the desired (set point) with valve position and is corrected by a precise digital signal to the stepper driver. This system provides a position accuracy of 0.036° with respect to set point. A 4-20 mA position signal feedback is provided. The acceleration/ deceleration profiles of the stepper-motor are optimized for speed and torque by the control logic. The controller is user configurable for: loss of signal action, loss of feed back action, set point/ valve position, calibration, valve action and hysteresis. An E 2 PROM is provided for storage of the configured parameters. The control system power requirement is 24 VDC at 8 Amps. The controller enclosure is NEMA 4 and must be mounted in a safe area. The enclosure can be mounted up to 300' from the valve. SpecificationsValve Controller (8412) Input Signal........................................................4-20 mA Signal Failure Mode...............................Freeze or Close (Configurable) Position Repeatability...........................................±0.05% Valve / Actuator (4280) VALVE Cv.......................................................See Model Coding ACTUATOR Drive..........................................................Stepper Motor
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This and other information from AMOT provide product or system options for further investigation by users having technical expertise. Before you select or use any product or system, it is important that you analyze all aspects of your application and review the information concerning the product in the current product catalog. The user, through its own analysis and testing, is responsible for making the final selection of the system and components and assuring that all performance, safety and warning requirements of the applications are met.
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