Hoses - Pressure Loss vs. Water Flow
Pressure loss in hoses due to water flow and friction.
Water flow through hoses and pressure loss due to friction:
Nominal diameters are used in the chart.
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Hazen-Williams Equation - calculate Head Loss in Water Pipes
- 1 psi = 6.9 kPa = 0.069 bar
- 1 ft (foot) = 0.3048 m
- 1 gal (US)/min = 6.30888×10-5 m3/s = 0.227 m3/h
| Hose Nominal Diameter (inches) | Internal Diameter (inches) |
|---|---|
| 1/8 | 0.125 |
| 3/16 | 0.1875 |
| 1/4 | 0.25 |
| 5/16 | 0.3125 |
| 3/8 | 0.375 |
| 7/16 | 0.4375 |
| 1/2 | 0.5 |
| 5/8 | 0.625 |
| 3/4 | 0.75 |
| 7/8 | 0.875 |
| 1 | 1 |
| 1 1/4 | 1.25 |
| 1 1/2 | 1.5 |
| 2 | 2 |
| 2 1/2 | 2.5 |
| 3 | 3 |
| 3 1/2 | 3.5 |
| 4 | 4 |
| 5 | 5 |
| 6 | 6 |
Example - Water Flow through a Hose and Pressure Loss
2 gpm (7.6 liter/min) flows through a 1/2" garden hose with length 82 feet (25 m). From the diagram above the pressure loss per 100 feet can be estimated to 5 psi. The pressure drop in the hose can be calculated as
(5 psi/100 ft) ((80 ft) / (100 ft)) = 4 psi (0.28 bar)
