Description: Critical speed (nk) is the rotational speed at which acting dynamic forces cause a machine component (e. g. shaft, rotor) to vibrate at its natural frequency (also referred to as intrinsic frequency, fi) and can even result in resonant vibrations throughout the entire machine and pump set; Name: crit. Speed
Description: Speed of rotation at which the frequency of vibration (or its multiples) corresponds to the rotor resonant (lateral or torsional) ; Name: Critical speed
Description: net positive suction head (NPSH) from flow rate at best efficiency point for actual impeller (indication of the minimum inlet pressure in meters required for the pump to deliver according to the QH curve. related to the optimum duty point at the current impeller diameter); Name: net positive suction head for Q opt at actual impeller size