
108 Practical Centrifugal Pumps
5.11 Pump characteristics – speed–torque curve
Centrifugal pumps are driven machines. They need to be coupled to prime movers like
electrical motors, IC engines, steam turbines, or gas turbines.
It is essential to rate and match the prime movers to the centrifugal pumps to insure
proper startup and operation of the train.
To match these two machines it is essential to know the speed–torque (N–T ) or the
mechanical characteristics of the pump.
The speed–torque characteristic of a pump is defined as the relation between the torque
on the shaft and the speed of rotation. These basically indicate the torque requi ...