Machines that extract energy from water heads and streams and convert it into shaft work — the functional inverse of a pump. Selection is governed by the available head × flow pair (specific speed).
Usual types
(handbooks per type in Phase 1)
- Pelton — impulse turbine (jet): high heads, low flows;
- Francis — reaction, radial-axial flow: the world's most widespread, medium heads and flows;
- Kaplan — reaction, axial propeller with adjustable blades: low heads, high flows;
- Bulb — compact Kaplan with the generator in a submerged bulb: run-of-river plants;
- Turgo — impulse, inclined jet: a niche between Pelton and Francis.
In process plants, energy recovery from pressurized liquids usually relies on hydraulic power recovery turbines (HPRT) — in practice, centrifugal pumps run in reverse; ISO 14224 defines no dedicated class for hydraulic turbines (testing and acceptance follow IEC 60193, the power-generation universe).
Reliability: runner cavitation (the same physics as pump cavitation, in the opposite direction), sediment erosion and blade fatigue dominate.