What is the friction loss per length for 65mm Hi-Combat?

• A. 25 kPa / length
• B. 50 kPa / length
• C. 100 kPa / length
• D. 75 kPa / length

Answer: (B)

Friction loss scales with hose size, flow, and length, and for a given flow the larger diameter hose carries less loss per metre. In practice, standard friction loss tables for a 65 mm Hi-Combat are read as a loss of about 50 kPa for every 100 metres of hose. That makes the per-length value 50 kPa per length (per 100 m). So the correct choice reflects this typical table value.

If you’re laying 200 m, you’d expect roughly 100 kPa of loss; 300 m would be about 150 kPa, and so on. This helps determine pump discharge pressure to maintain the desired nozzle pressure.