FAA Powerplant Written Practice Test

What valve often works in conjunction with the start valve to supply air to the pneumatic starter?

1. Throttle valve

2. Pressure-regulating and shutoff valve

3. Intake valve

4. Fuel control valve

The correct answer is: Pressure-regulating and shutoff valve

The pressure-regulating and shutoff valve is key in pneumatic starter systems because it is responsible for controlling the air pressure supplied to the starter. When the pneumatic starter is engaged, this valve regulates the airflow to ensure that the starter receives the appropriate air pressure needed to function effectively. This regulation is critical to prevent damage from excessive pressure and to ensure reliable starter operation. In conjunction with the start valve, the pressure-regulating and shutoff valve helps manage the energy delivered to the starter, which is essential during engine start-up. It can also control the airflow after the start process is complete, ensuring that the pneumatic system operates efficiently and safely. Understanding the role of this valve is crucial for anyone working with engine start systems and their components.