TCL have developed a bleed valve position monitor which provides a positive indication of the gas generator bleed valves. The bleed valve monitors can be connected to an existing PLC / SCADA system to provide real-time monitoring of your gas generators bleed valves. The PLC / SCADA can also be programmed to display historical and real-time trending facilities.
The bleed valve position sensing system uses high temperature switches fitted to the housing-bearing for the bleed valve slide ball pin. This allows feedback to the turbine control system to determine if the bleed valve is fully open or closed.
Each switch contains a dry contact, normally open 2 wire device that is wired back to the engine Junction box using the high
temperature cable supplied. To comply with ATEX requirements, Intrinsically Safe barriers or Galvanic Isolators can be provided if required for both the VIGV monitor and the bleed valve monitor.
| High Temperature Switch |
| Switch Structure |
Dry contact |
| Output Mode |
A: Normally open |
| Both ON à OFF, OFF à ON/ 0.01 *1 |
| Repeatability |
(At operating speed 50 ~ 200 mm/min) *2 |
| Movement Differential |
0 |
| Contact life time |
3 million |
| Temperature drift |
0 (because of no amplifier) |
| Oscillation |
| Impact |
300 m/s for X,Y,Z each direction |
| 5-24V DC |
| Contact Rating |
Steady current: 10 mA or less
Rush current: 20 mA or less |