ANNEX ISupplementary provisions
ANNEX I Definitions applicable for the purposes of Annexes II to V For the purpose of Annexes II to V, the following definitions apply: (1) ‘ Impeller ’ means the rotating component of a rotodynamic pump which transfers energy to the water; (2) ‘ Full impeller ’ means the impeller with the maximum diameter for which performance characteristics are given for a pump size in the catalogues of a water pump manufacturer; (3) ‘ Specific speed ’ (n s ) means a dimensional value characterising the shape of the water pump impeller by head, flow and speed (n): [min –1 ] Where — ‘ Head ’ (H) means the increase in the hydraulic energy of water in meters [m], produced by the water pump at the specified point of operation, — ‘ Rotational speed ’ (n) means the number of revolutions per minute [rpm] of the shaft, — ‘ Flow ’ (Q) means the volume flow rate [m 3 /s] of water through the water pump, — ‘S tage ’ (i) means the number of series impellers in the water pump, — ‘ Best efficiency point ’ (BEP) means the operating point of the water pump at which it is at the maximum hydraulic pump efficiency measured with clean cold water, (4) ‘ Hydraulic pump efficiency ’ (η) is the ratio between the mechanical power transferred to the liquid during its passage through the water pump and the mechanical input power transmitted to the pump at its shaft; (5) ‘ Clean cold water ’ means clean water to be used for pump testing, with a maximum kinematic viscosity of 1,5 × 10 –6 m 2 /s, a maximum density of 1 050 kg/m 3 and a maximum temperature of 40 °C; (6) ‘ Part load ’ (PL) means the operating point of the water pump at 75 % of the flow at BEP; (7) ‘ Over load ’ (OL) means the operating point of the water pump at 110 % of the flow at BEP; (8) ‘ Minimum Efficiency Index ’ (MEI) means the dimensionless scale unit for hydraulic pump efficiency at BEP, PL and OL; (9) ‘ C ’ means a constant for each specific water pump type quantifying the differences in efficiency for different pump types.