Total dynamic head (TDH) is the sum of suction lift, discharge head, tank elevation and friction losses. The table below relates pressure at the pump outlet to equivalent water head.
| Pressure (bar) | Head (m) | Equivalent lift |
|---|---|---|
| 0.5 | 5.1 | 2-storey building |
| 1.0 | 10.2 | 3-storey building |
| 1.5 | 15.3 | 4-storey building |
| 2.0 | 20.4 | 5-storey building |
| 3.0 | 30.6 | Small apartment block |
| 4.0 | 40.8 | Medium apartment block |
| 6.0 | 61.2 | High-rise booster |
| 10.0 | 102.0 | High-pressure RO feed |
Friction losses: Add 5-15% to measured static head for pipe friction, valves and fittings. For long pipelines, calculate losses using the Hazen-Williams or Darcy-Weisbach equation.