Length Distance
Available pressure avail = P_pump − P_nozzle − ρg·Δh (Δh elevation m); friction loss per metre per_m = 10.67·Q^1.852/(C^1.852·D^4.87)×0.00980665; max supply distance L_max = avail/per_m.
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Horizontal supply distance | L = P2/(αQ²) from rated pressure | Fire hydraulics handbook |
| Vertical supply | ≈0.1 MPa per 10 m elevation | Hydrostatics |
| Pumper inlet | ≤1000 m relay distance | GB 50974-2014 §7 |
| Hose rating | 1.6 MPa working pressure | GB 6246-2011 |
| Safety factor | ≤0.8× rated pressure | GB 6246-2011 §5 |
| Relay pump | 400–600 m between relay pumps | IFSTA manual |
根据消防泵出口压力、所需出口压力、地形高差与水带规格,估算单条供水干线能够达到的最大有效供水距离,用于火场供水方案规划。