Which component of the air brake system helps to dry out the compressed air?

The component of the air brake system that helps to dry out the compressed air is the drier. This device plays a critical role in ensuring that air entering the braking system is free of moisture, which can lead to various issues in air brake systems. Moisture in the compressed air can cause corrosion, freezing, and malfunction of brake components.

The air dryer removes moisture and contaminants through a filtration system, typically using a desiccant material that absorbs water vapor. By effectively drying the air, the drier ensures that the air brake system operates efficiently and safely, preventing problems during braking.

In contrast, while the governor regulates the pressure within the system and the supply tank stores compressed air, they do not specifically address moisture removal. The safety valve, on the other hand, is designed to release excess pressure to prevent system overload but does not have any function related to drying the air. Therefore, the drier is essential for maintaining the integrity and performance of the air brake system by managing moisture content effectively.