Description: nominal plane specified by a measurement standard to ensure comparability of results; Name: reference level
Description: horizontal plane for use as the datum for height measurement; Name: Reference plane
Description: Speed that characterizes a pump in terms of its speed, flow rate per impeller eye, i.e. total flow for single-flow impeller, half flow for double-flow impeller, at the best efficiency point and head per stage at maximum impeller diameter ; Name: Specific speed