EGV Gas Valve

The EGV gas valve is made up of the following components:

  • ATEX approved DC servo motor, fitted with:
    • Encoder for position feedback.
    • Motor winding temperature detection.
  • Ultra low backlash gearbox to provide high torque.
  • 'V' notch ball valve.
    • Square law flow profile for accurate light-off flow control.
    • Self cleaning nature of the valve results in low sensitivity to contamination.
    • Trunion style bearings are not exposed to the fuel gas.
  • Minimum light-off position limit switch.

Servo Drive

The valve can be supplied with or without the servo drive which comes with the following options:
  • Acceleration/deceleration limit control.
  • Gas supply pressure/temperature compensation.
  • Valve de-choking compensation.
EGV-3000 Series Gas Valve

Electrically actuated gas valves to replace OEM hydraulically and electrically actuated valves.

  • Sizes available for gas turbines from 1MW to 150MW.
  • Remove hydraulic oil pumps and associated maintenance, no more oil leaks.
  • Accurate and repeatable valve positioning gives reliable light-off.
  • Pressure and temperature compensation options available.
  • A brushless DC servo motor is used to position the valve in response to a control signal from the governor.
  • The motor drives the valve through a low backlash 42:1reduction gearbox.
Specifications
Hazardous area certification ATEX Zone 1, Group IIB, T4
Servo supply voltage 110/240 Vac or 110/24 Vdc 
Pressure rating ANSI/150/300/600
Servo power rating 200W
Output torque 50 Nm
Closing time  < 0.15 s
Position accuracy > 0.05 deg
Fuel filtration at inlet port better than 15 micron
Max throttle valve effective area 0.2 to 5.0 sq. inch
Rotary travel range 90 deg
Rate of travel < 150mS per 90 degrees
Metering spindle material Stainless Steel
Metering shoe material Bronze
Seals Viton
Gas temperature Max. 80 deg C
Ambient temperature Max. 100 dg C

High driving torque and the self-cleaning nature of the valve results in low sensitivity to contamination. A limit switch is used to provide independent indication that the valve is nominally at light-off position.

TCL have developed gas valve systems for a number of gas turbines including:

  • Rolls Royce.
  • Solar.
  • GE Frame engines.
  • GE Aeroderivative.
  • Ruston.
  • Siemens.

These systems are calibrated to replicate the existing valve calibration and can be fitted without modifying the control system.
The gas valve is available in the following sizes:

Valve Series Turbine rating MWe Approx. Gas flow
EGV-3000 1 to 3MW  0 to 2,000 pph
EGV-8000 2 to 8MW 0 to 6,000 pph
EGV-20,000 10 to 15MW 0 to 12,000 pph
EGV-50,000 12 to 30MW 0 to 25,000 pph
EGV-75,000 25 to 60MW 0 to 40,000 pph
EGV-100,000 50 to 100MW 0 to 70,000 pph
EGV-150,000 80 to 150MW 0 to 90,000 pph