For ladders with a vertical height of 110 feet or less, the friction loss between the monitor and the point below at 1000 gpm shall not exceed how many psi?

• A. 50 psi
• B. 100 psi
• C. 150 psi
• D. 200 psi

Answer: (B)

The main idea is to limit pressure loss in the hose/line feeding the monitor so you still have enough pressure at the nozzle when delivering water at a high flow through an aerial setup. For ladders up to 110 feet tall, at 1000 gallons per minute, the allowed friction loss from the monitor back to the point below is capped at 100 psi. Keeping this loss within 100 psi ensures the nozzle can maintain effective pressure and reach without needing excessive pump pressure, even with the elevation gain.

If friction loss were much lower (like 50 psi), you’d be constraining the system unnecessarily at that flow, potentially underutilizing the pump and limiting performance. If it were much higher (150 or 200 psi), the pressure at the monitor would drop too far, degrading the stream and reach. So 100 psi is the balanced limit for this height and flow.