1. Vibrations in operation 1. Pipe support is not stable, the pump base or anchor bolts loose is the common cause of vibration, bolts must be fastened around to avoid loosening. 2. Liquid gas, carefully check the pump and inlet pipe sealing surface bolts are loose, the gasket is damaged, the pump and piping system components are damaged. 3. Pump and motor shaft is not the heart, should be adjusted, with the belt rotation, the rotating belt is too loose or poor contact, can also cause vibration. Pump impeller imbalance in the operation of the impeller wear and tear or individual impeller runner clogging easily lead to vibration, sometimes due to shaft bending impeller bad balance caused by vibration. Second, the operation of noise increases 1. Bearing noise: the sound source bearing installation site, usually with a screwdriver or screwdriver to place the bearing installation, with ears, as crashed sound. Motor noise: General is howling, can only replace the motor. Cavitation noise: the sound source in the pump chamber, crackling crackling sound. Third, the motor hot Chinese pump technology forum motor outer wall may be hot, super-current operation may be closed small outlet valve, adjust to run within the rated current, it may be the motor coil quality problems, it can only replace the motor. 2 rotating parts appear friction, frictional resistance increases, it may over-current so that the motor should be shut down to check the rotor is flexible. Motor bearing fever, the bearing may be lack of oil or damage, the need to repair or replace the bearing. Working voltage is too low, check the circuit to adjust the voltage.