Manitoba Airbrake Practice Exam

The safety valve is designed to open and release excess air when the pressure inside a system reaches a certain level. It is important for this valve to only open when necessary to prevent malfunction or damage to the system. The other options, A, B, and D, may be too low or too high of a pressure for the safety valve to properly function. Option C, at 150 psi, is the most likely pressure level for the safety valve to open and release excess air. Therefore, it is the correct answer.