The first critical speed of pumps and motors

The first critical speed of pumps and motors shall be at least 30% greater than rated operating speed (no critical speeds are allowed below the rated speed of the pump). The shaft rotor dynamic characteristics, number of blades, dimensions and clearances, bearing span, etc. which might be related to the critical speed must be fully analysed. The Supplier will assure that the pump design is resonance-free throughout all the operation range.