Practice question

What is the 'safety valve' on an air brake reservoir, and at what pressure is it set to open?

It releases pressure if the compressor governor fails, set to open at 150 psi (1,034 kPa)
It releases pressure to engage the parking brakes, set to open at 60 psi
It drains water, set to open at 200 psi
It cuts off the air supply to the steering axle, set to open at 90 psi

Answer: A — It releases pressure if the compressor governor fails, set to open at 150 psi (1,034 kPa)

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