-The 9th stage air IN and OUT pipes.
EFG
.
.
.
CTC-201-213-02
EFFECTIVITY
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ALL CFM56-5B ENGINES FOR A319-A320-A321
ENGINE SYSTEMS Jan 03
CFMI PROPRIETARY INFORMATION
CFM56-5B TRAINING MANUAL
EFG
TRANSIENT BLEED VALVE
TBV actuator.
The TBV includes a linear actuator linked to a butterfly
valve.
The actuator is attached to a fuel port pad that has three
holes:
-Fuel drain.
-Pcr to Rod end.
-Pc, or Pb, to Head end. Two electrical connectors are directly fitted on the TBV actuator, next to the fuel supply plate.
EFG
CTC-201-215-01
EFFECTIVITY
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ALL CFM56-5B ENGINES FOR A319-A320-A321
ENGINE SYSTEMS Jan 03
CFMI PROPRIETARY INFORMATION
CFM56-5B TRAINING MANUAL
EFG
TRANSIENT BLEED VALVE
The TBV is a single actuator, butterfly-type shut-off valve, that has two positions, OPEN or CLOSED. The valve is normally closed.
The fuel supply pressure to the the opening chamber is held constant through port Pcr.
With the pressure in the opening chamber held constant, a variation of the fuel pressure (Pc, or Pb) in the closing chamber, determines the valve position.
The butterfly valve shuts off the airflow when fuel pressure increases in the closing chamber.
As the fuel supply pressure reduces in the closing chamber, the actuator piston strokes toward the open position.
The piston incorporates an orifice for cross piston fuel flow, providing actuator cooling.
A drain port is provided to route any fluid leakage past the shaft seal to the drain mast.
The valve position is monitored by the ECU, through a dual channel LVDT connected to the actuator. The LVDT supplies a feedback signal which corresponds to the butterfly position.
In the failsafe position, the piston goes to the open position.
EFG
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CTC-201-216-02
EFFECTIVITY
75-26-00 Page 7
ALL CFM56-5B ENGINES FOR A319-A320-A321
ENGINE SYSTEMS Jan 03
CFMI PROPRIETARY INFORMATION
CFM56-5B TRAINING MANUAL
EFG
TRANSIENT BLEED VALVE
According to a schedule, the ECU sends a valve position demand to the HMU.
The dedicated servo valve within the HMU changes the electrical information into fuel pressure and sends it to the TBV.
The dual channel LVDT sends the valve position to the ECU, as feedback information, to be compared with the position demand.
If the valve position does not match the demand, the ECU sends a signal, through the HMU, to change the valve state until both terms are equal.
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