PAT - pumps as turbines

PAT (pumps as turbines) are non-regulated reaction Francis turbines. PAT does not have an inlet adjustable guide vane, which brings a simple and rugged construction. Operation across a wide range makes PAT highly versatile and reliable, especially for existing water supply systems. Since compact units (turbine / generator) are available for different duty points / system configurations, the payback time is short.o
PAT are usually installed as bypass circuits for pressure control valves, converting the hidraulic energy dissipated on those valves into electric energy. Flow control can be achieved by: Speed control Bypass or throttling valves Cascading fractional units
PAT covers a 20-200 m head and 50-500 l/sec. flow, being economically viable within 20 – 500 kW power range. While several constructive variants (horizontal or vertical, single or double volute, etc.) of PAT are available, the operating conditions have to be carefully calculated.