In air brake systems, what does PSI stand for?

PSI stands for "Pounds per square inch," a unit of pressure commonly used to measure the air pressure in various systems, including air brake systems in vehicles. In these systems, maintaining the correct PSI is crucial for proper brake function, as it ensures that the air brake components operate effectively. The air pressure must be sufficient to engage and disengage the brakes reliably when needed, ensuring safety for the driver and others on the road. Understanding PSI and its importance in air brake systems is fundamental for anyone operating or maintaining vehicles equipped with air brakes.