What does the large red knob on the second stage regulator do?

What does the large red knob on the second stage regulator do?

• A. It resets the regulator to default
• B. It adjusts the cylinder pressure
• C. It opens the bypass valve
• D. It controls the adjustable bypass valve and when closed, it provides a constant flow of air at a maximum of 120 L per minute

Answer: (D)

The large red knob on the second stage regulator controls the adjustable bypass valve. This valve lets air bypass the normal demand mechanism, providing a steady, constant flow when needed. When the bypass is in the closed position, it delivers a continuous flow of air up to about 120 liters per minute, regardless of how you breathe. This function is separate from adjusting cylinder pressure (handled by the first stage) and from resetting the regulator. So the knob’s purpose is to set the bypass flow, which is why this option is the correct description.

The large red knob on the second stage regulator controls the adjustable bypass valve. This valve lets air bypass the normal demand mechanism, providing a steady, constant flow when needed. When the bypass is in the closed position, it delivers a continuous flow of air up to about 120 liters per minute, regardless of how you breathe. This function is separate from adjusting cylinder pressure (handled by the first stage) and from resetting the regulator. So the knob’s purpose is to set the bypass flow, which is why this option is the correct description.