Friction Loss CoefficientsComment on this page
IFSTA “Single Hoselines”
Pumping Apparatus Driver/Operator Handbook, 2nd edition
Assumes FL = C x (Q ÷ 100)² x (L ÷ 100)
Hose Size | Coefficient (C) |
---|---|
20mm booster | 1741.0 |
25mm booster | 238.0 |
32mm booster | 127.0 |
38mm | 38.0 |
45mm | 24.6 |
50mm | 12.7 |
65mm | 3.17 |
70mm with 77mm couplings | 2.36 |
77mm with 65mm couplings | 1.27 |
77mm with 77mm couplings | 1.06 |
90mm | 0.53 |
100mm | 0.305 |
115mm | 0.167 |
125mm | 0.138 |
150mm | 0.083 |
Standpipes | Coefficient (C) |
100mm | 0.600 |
125mm | 0.202 |
150mm | 0.083 |
Single Line (Fireground Coefficients)
These are friction loss coefficients that I had on a printed sheet of paper from a pump course I participated in several years ago. I don’t know where they came from. Based on the values I suspect that these assume L to be # of 30m sections. – Matt Adams
Hose Size | Coefficient |
---|---|
20mm booster | 522 |
25mm booster | 71 |
32mm booster | 38 |
38mm booster | 11 |
45mm with 38mm couplings | 7 |
50mm | 4 |
65mm | 1 |
70mm with 77mm couplings | 1.7 |
77mm with 65mm couplings | 0.4 |
77mm with 77mm couplings | 0.3 |
90mm | 0.2 |
100mm | 0.1 |
115mm | 0.05 |
125mm | 0.04 |
150mm | 0.025 |
Siamesed Lines of Equal Length (Fireground Coefficients)
These are friction loss coefficients that I had on a printed sheet of paper from a pump course I participated in several years ago. I don’t know where they came from. Based on the values I suspect that these assume L to be # of 30m sections. – Matt Adams
Hose Size | “C” @ 2 Lines | “C” @ 3 Lines |
---|---|---|
65mm | .250 | .111 |
70mm with 77mm couplings | .177 | .079 |
77mm with 65mm couplings | .095 | |
77mm with 77mm couplings | .079 |