In the maintenance process, the diagnosis of pump failure is a key part of the following are given several common failures and elimination measures for you to set the pump fault diagnosis. 1, no liquid to provide insufficient liquid supply or insufficient pressure 1) the pump is not filled with water or without proper exhaust Elimination measures: Check the pump housing and inlet pipe are all filled with liquid. 2) too low speed Elimination measures: Check the motor wiring is correct, the voltage is normal or the turbine steam pressure is normal. 3) the system head too high Elimination measures: Check the system head (especially friction loss). 4) Suction too high Elimination measures: Check the existing net head (inlet pipe is too small or too long will cause great friction loss). 5) Impeller or pipeline plugging Elimination measures: Check for obstructions. 6) Direction of rotation is not the elimination of measures: Check the direction of rotation. 7) Air or inlet line leaks. Check for leaks in the inlet line for cavitation and / or air. 8) Stuffing or seal wear in the stuffing box to allow air to leak into the pump casing Elimination measures: Check the packing or seal and replace as required to check that the lubrication is normal. 9) When pumping hot or volatile liquid Inadequate suction head Elimination measures: Increase the suction head, consult the manufacturer. 10) Bottom valve too small Elimination measures: Install the correct size of the bottom valve. 11) At the end of the valve or inlet pipe immersion depth is not enough Elimination measures: Consult manufacturers for the correct immersion depth. Eliminate eddies with baffles. 12) impeller clearance is too large Elimination measures: check the gap is correct. 13) Impeller damage elimination measures: Check the impeller, as required replacement. 14) Impeller diameter is too small Elimination measures: Consult factory for correct impeller diameter. 15) Pressure gauge position is not correct Elimination measures: Check the location is correct, check the outlet nozzle or pipe. 2, pump operation will shut down after a while 1) Suction too high Elimination measures: Check the existing net head (inlet pipe is too small or too long will cause a great friction loss). 2) impeller or pipeline plugging measures to eliminate: check for any obstructions. 3) Air or inlet line leaks. Check for leaks in the inlet line for cavitation and / or air. 4) Stuffing or seal wear in stuffing box to allow air to leak into pump housing. Removal Action: Check packing or seal and replace as required. Check the lubrication is normal.