How To Diagnose A Fire Pump Malfunction?
Dec 05, 2024
As the name suggests, fire pumps are pumps used in firefighting and are classified into different types according to different classification methods. Fire pumps are widely used in environmental protection, water treatment, fire protection and other departments to pump various liquids due to their fully sealed, leak free and corrosion-resistant characteristics.
The selection criteria for anti pump should be considered from some aspects based on the process flow and water supply and drainage requirements. The diagnosis of fire pump faults is a crucial step in the maintenance process of fire pumps. The following are several common faults and their elimination measures for everyone to diagnose fire pump faults.
1. No liquid provided, insufficient supply of liquid or insufficient pressure
1) The pump has not been filled with water or has not been properly vented
Elimination measures: Check if the pump casing and inlet pipeline are completely filled with liquid.
2) The speed is too low
Elimination measures: Check if the wiring of the motor is correct, if the voltage is normal, or if the steam pressure of the turbine is normal.
3) The system head is too high
Elimination measures: Check the water head of the system (especially friction loss).
4) The suction distance is too high
Elimination measures: Check the existing net pressure head
5) Impeller or pipeline blockage
Elimination measures: Check for obstacles.
6) Wrong rotation direction
Elimination measures: Check the direction of rotation.
7) Air generation or leakage in the inlet pipeline
Elimination measures: Check for air pockets and/or air leaks in the inlet pipeline.
8) The packing or seal in the stuffing box is worn, causing air to leak into the pump casing
Elimination measures: Check the packing or seal and replace it as needed, check if the lubrication is normal.
9) Insufficient suction head when pumping hot or volatile liquids
Elimination measures: Increase the suction head and consult with the manufacturer.
10) The bottom valve is too small
Elimination measures: Install bottom valves of the correct size.
11) Insufficient immersion depth of bottom valve or inlet pipe
Elimination measures: Consult the manufacturer for the correct immersion depth. Eliminate eddy currents with baffles.
12) The clearance between the impeller is too large
Elimination measures: Check if the gap is correct.
13) Damaged impeller
Elimination measures: Check the impeller and replace it as required.
14) The diameter of the impeller is too small
Elimination measures: Consult the manufacturer for the correct impeller diameter.
15) The position of the pressure gauge is incorrect
Elimination measures: Check if the position is correct and inspect the outlet nozzle or pipeline.
2. The fire pump will shut down after running for a while
1) The suction distance is too high
Elimination measures: Check the existing net pressure head
2) Impeller or pipeline blockage
Elimination measures: Check for obstacles.
3) Air generation or leakage in the inlet pipeline
Elimination measures: Check for air pockets and/or air leaks in the inlet pipeline.
4) The packing or seal in the stuffing box is worn, causing air to leak into the pump casing
Elimination measures: Check the packing or seal and replace it as needed. Check if the lubrication is normal.
5) Insufficient suction head when pumping hot or volatile liquids
Elimination measures: Increase the suction head and consult with the manufacturer.
6) Insufficient immersion depth of bottom valve or inlet pipe
Elimination measures: Consult the manufacturer for the correct immersion depth and use a baffle to eliminate eddy currents.
7) The sealing gasket of the water pump casing is damaged
Elimination measures: Check the condition of the sealing gasket and replace it as required.
3. The power consumption of the fire pump is too high
1) Wrong rotation direction
Elimination measures: Check the direction of rotation.
2) Damaged impeller
Elimination measures: Check the impeller and replace it as required.
3) Rotating components bite to death
Elimination measures: Check whether the clearance of internal worn parts is normal.
4) Axis bending
Elimination measures: Straighten the shaft or replace it as required.
5) The speed is too high
Elimination measures: Check the winding voltage of the motor or the steam pressure delivered to the turbine.
6) The water head is lower than the rated value. Too much liquid is being pumped
Elimination measures: Consult with the manufacturer. Install throttle valve and cut impeller.
7) The liquid is heavier than expected
Elimination measures: Check the specific gravity and viscosity.
8) The stuffing box is not filled correctly
Elimination measures: Check the packing and reload the packing box.
9) Incorrect lubrication of bearings or wear of bearings
Elimination measures: Check and replace as required