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. 5) When pumping hot or volatile liquid Inadequate suction head Elimination measures: Increase the suction head, consult the manufacturers. 6) The end of the valve or inlet pipe immersion depth is not enough Elimination measures: Consult factory for the correct immersion depth, with a baffle to eliminate eddy currents. 7) Damage to the pump housing gasket: Check the condition of the gasket and replace it as required. 3, the pump power consumption is too large 1) the direction of rotation is not the elimination of measures: Check the direction of rotation. 2) Impeller damage elimination measures: Check the impeller, as required to be replaced. 3) Rotating parts bite Elimination measures: Check the internal wear parts of the gap is normal. 4) Shaft bending elimination measures: Alignment shaft or according to the requirements of the replacement. 5) Too high speed Elimination measures: Check motor winding voltage or steam pressure delivered to the turbine. 6) head below the rated value. Pump too much liquid Elimination measures: consult factory. Install throttle valve, cut impeller. 7) liquid heavier than the expected value Elimination measures: Check the proportion and viscosity. 8) The stuffing box does not have the correct stuffing (insufficient stuffing, incorrect stuffing or running-in, stuffing is too tight). Remedy: Check the stuffing and refill stuffing box. 9) Bearing lubrication is not correct or bearing wear Elimination measures: Check and replace as required. 10) The running clearance between wear rings is not correct Elimination measures: Check the clearance is correct. Replace the wear rings of the pump housing and / or impeller as required. 11) pump casing stress too much Elimination measures: eliminate stress and factory representatives advice. After eliminating the stress, check the alignment. 4, pump stuffing box leak too much 1) shaft bending elimination measures: straightening axis or according to the requirements of the replacement. 2) Misalignment of the coupling or pump and drive Elimination: Check the alignment and re-center if necessary. 3) Bearing lubrication is not correct or bearing wear Elimination measures: Check and replace as required. 5, the bearing temperature is too high 1) shaft bending elimination measures: straightening axis or according to the requirements of the replacement. 2) Misalignment of the coupling or pump and drive Elimination: Check the alignment and re-center if necessary. 3) Bearing lubrication is not correct or bearing wear Elimination measures: Check and replace as required. 4) Too much stress on the pipe of the pump casing Elimination measures: Eliminate the stress and consult the manufacturer's representative. After eliminating the stress, check the alignment. 5) too much lubricant Elimination measures: remove the plug, so that too much fat automatically discharged. If it is an oil-lubricated pump, drain the oil to the correct oil level. 6, Overheating of stuffing box 1) Filling or seal wear in stuffing box to let air leak into pump casing. Measures to eliminate: Check packing or seal and replace if necessary. Check the lubrication is normal. 2) The stuffing box does not have the correct stuffing (insufficient stuffing, incorrect stuffing or running-in, stuffing is too tight). Remedy: Check the stuffing and refill stuffing box. 3) packing or mechanical seal design problems Elimination measures: Consult factory. 4) mechanical seal damage elimination measures: check and replace as required. Consult the manufacturer. 5) Shaft scratch removal measures: repair, re-machining or replacement as required. 6) The packing is too tight or the mechanical seal is not properly adjusted. Removal measures: Check and adjust the packing and replace as required. Adjust the mechanical seal (refer to the manufacturer's instructions provided with the pump or consult the manufacturer). 7, Rotating parts are difficult to rotate or have a friction 1) Axis bending measures to eliminate: straighten the shaft or be replaced as required. 2) Correct running clearance between wear rings Elimination measures: Check that the clearance is correct. Replace pump housing or impeller wear ring as required. 3) The pressure on the pump casing is too high