Description: Difference of the total energy head at the outlet side of the pump to the total energy head at the inlet side of the pump; Name: energy circulating lift of the pump
Description: difference between the total head at the outlet side of the pump and the total head at the inlet side of the pump; Name: lift circulating pump
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