The use of asphalt insulation pumps in the industry

In a typical centrifugal oil pump, the power always increases with the increase of flow rate, that is to say, the power curve is a curve that rises with the increase of flow rate. This poses a problem for the use of asphalt insulation pumps: when the pump is running at the operating point, the power of the pump is less than the rated power of the motor, and the use of this pump is correct; But when the pump head decreases, the flow rate will increase (as can be seen from the pump's performance curve), and the power will also increase accordingly. When the flow rate exceeds the operating point flow rate and reaches the value, the input power of the asphalt insulation pump may exceed the rated power of the motor, causing the motor to overload and burn out. When the motor is overloaded, either the protection system will activate to stop the pump from rotating; Either the protection system fails and the motor burns out.