The Secondary Pressure Reducer sends air to the regulator for Vibralert within which pressure range?

• A. 85-110 psig
• B. 145-165 psig
• C. 60-90 psig
• D. 110-140 psig

Answer: (B)

The Vibralert needs a stable, mid-range supply from the secondary pressure reducer to operate reliably. That supply is specified to be within about 145–165 psig. Keeping the inlet to the Vibralert regulator in this narrow window lets the alarm function consistently as the system’s air pressure changes, independent of the primary regulator output. If the feed were too low, the Vibralert might not trigger; if it were outside this range, the regulator could’t maintain the proper output for the alarm. So, 145–165 psig is the designed range to feed the Vibralert circuit.