Which statement correctly describes the role of the pressure reducers?

Which statement correctly describes the role of the pressure reducers?

• A. The secondary reducer feeds the Vibralert regulator at 145-165 psig
• B. The secondary reducer feeds the normal respiration regulator
• C. The primary reducer feeds the Vibralert regulator at 145-165 psig
• D. The primary reducer feeds the low pressure purge valve

Answer: (A)

The idea here is that the SCBA uses two regulators to supply different parts of the system. The primary reducer drops the cylinder pressure down to the level used by the normal respiration regulator, feeding the breathing path. The Vibralert low‑air warning device needs its own, separate feed from the secondary reducer, at about 145–165 psi. This dedicated feed lets the warning system operate reliably as gas pressure changes, independent of the breathing regulator flow. That’s why the statement that the secondary reducer feeds the Vibralert regulator at 145–165 psig is the correct description. The other arrangements don’t fit how the system is designed: the normal respiration regulator isn’t fed from the secondary reducer, the Vibralert isn’t fed from the primary reducer, and purge functions aren’t supplied from the primary reducer in this configuration.

The idea here is that the SCBA uses two regulators to supply different parts of the system. The primary reducer drops the cylinder pressure down to the level used by the normal respiration regulator, feeding the breathing path. The Vibralert low‑air warning device needs its own, separate feed from the secondary reducer, at about 145–165 psi. This dedicated feed lets the warning system operate reliably as gas pressure changes, independent of the breathing regulator flow. That’s why the statement that the secondary reducer feeds the Vibralert regulator at 145–165 psig is the correct description. The other arrangements don’t fit how the system is designed: the normal respiration regulator isn’t fed from the secondary reducer, the Vibralert isn’t fed from the primary reducer, and purge functions aren’t supplied from the primary reducer in this configuration.