Description: relationship between the efficiency of the pump and the rate of flow at given operating/rated conditions of speed and liquid; Name: efficiency curve of the pump
Description: relationship between the total head of the pump and the rate of flow at given operating conditions /rated conditions of speed and liquid; Name: Pump efficiency curve
Description: input variable to a comparing element in a controlling system, which sets the desired value of the controlled variable and is deducted from the command variable; Name: reference variable