What are the ways to prevent common failures of fire pumps in advance?
Oct 17, 2022
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For machinery and equipment, targeted prevention of common failures is far better than repairing after damage, especially for equipment like fire pumps, whether the normal use and high efficiency of the use of the lives of millions of people and property security. Therefore, it is necessary to keep the fire pump in a good condition so that it can be put into rescue quickly in case of accidents. Today, Xizhiquan teaches you some common failures of fire pumps, such as gas binding, cavitation, motor overload and other methods of prevention in advance, to help you better maintain and use centrifugal fire pumps.
First, the prevention of fire pump gas binding phenomenon
Centrifugal fire pump should be filled with fluid before starting, in order to drain the air accumulated in the pump casing. Ensure that the bottom valve of the suction line has good closure when filling the pump. If it is a centrifugal pump with automatic pumping system, make sure the automatic pumping system works normally. If you need to start the pump within a short time after stopping it, you can not empty it, but check whether the pump is full of liquid before starting next time.
Regularly check the air tightness of the suction pipeline to prevent poor sealing inlet air, in order to avoid the re-emergence of gas binding phenomenon in the pump during operation and affect the work.
Second, the prevention of fire pump cavitation phenomenon
1, Control, adjust the installation height of the pump, so that the installation height between the suction port of the pump and the liquid surface as close as possible, the difference should not be too large. Especially mobile fire pump, if the normal suction and discharge of liquid, it is possible that the installation height is not appropriate, by reducing the installation height or pouring installation, often can be solved and the pump is not easily damaged.
2, You can add a small capacity storage tank in front of the pump, in order to increase the height of the liquid level, improve the static pressure, so as to shorten the distance between the liquid level of the inhalation storage tank and the pump inlet, to prevent cavitation phenomenon.
3, By reducing the pump inhalation pipeline flow resistance loss, can also effectively prevent cavitation phenomenon. Within the allowed range, try to shorten the length of the inhalation pipeline, less elbows, valves and other fittings, appropriately increase the diameter of the inhalation pipeline, regular inspection of the inhalation pipeline, screen and bottom valve to prevent blockage and increase the resistance to liquid flow.
4、By improving the strength and anti-abrasion of pump material, it can effectively reduce the erosion of pump by cavitation, so as to reduce the damage of pump by cavitation and prolong its service life. In the structural design of the pump, by adding an induction wheel in front of the impeller of the centrifugal pump can also improve the anti-cavitation performance.
Three, to prevent the fire pump motor overload
1, The pump should check whether the export valve is in a fully closed state before starting, in order to prevent the motor from burning out due to excessive starting current.
2、Correctly choose the matching motor with the pump performance parameters to prevent the motor power is too small and overload long time operation.
3、Check the power supply voltage and current of each phase according to the technical parameters of the motor to ensure the error is within 3%. Remove the motor, check the rotation flexibility of the gear box shaft assembly and pump impeller and induced wheel, drain the liquid to find out if there is any mechanical failure, etc.
Fourth, to prevent abnormal vibration and wear of the fire pump
1, The pump installation to be secure, to regularly check its solidity, especially the foot or back bolts, to prevent fasteners loose.
2、Strengthen monitoring by monitoring the vibration waveform when the pump is running, and regularly check and repair the wear between the impeller and the sealing ring to find and eliminate hidden problems in time.
First, the prevention of fire pump gas binding phenomenon
Centrifugal fire pump should be filled with fluid before starting, in order to drain the air accumulated in the pump casing. Ensure that the bottom valve of the suction line has good closure when filling the pump. If it is a centrifugal pump with automatic pumping system, make sure the automatic pumping system works normally. If you need to start the pump within a short time after stopping it, you can not empty it, but check whether the pump is full of liquid before starting next time.
Regularly check the air tightness of the suction pipeline to prevent poor sealing inlet air, in order to avoid the re-emergence of gas binding phenomenon in the pump during operation and affect the work.
Second, the prevention of fire pump cavitation phenomenon
1, Control, adjust the installation height of the pump, so that the installation height between the suction port of the pump and the liquid surface as close as possible, the difference should not be too large. Especially mobile fire pump, if the normal suction and discharge of liquid, it is possible that the installation height is not appropriate, by reducing the installation height or pouring installation, often can be solved and the pump is not easily damaged.
2, You can add a small capacity storage tank in front of the pump, in order to increase the height of the liquid level, improve the static pressure, so as to shorten the distance between the liquid level of the inhalation storage tank and the pump inlet, to prevent cavitation phenomenon.
3, By reducing the pump inhalation pipeline flow resistance loss, can also effectively prevent cavitation phenomenon. Within the allowed range, try to shorten the length of the inhalation pipeline, less elbows, valves and other fittings, appropriately increase the diameter of the inhalation pipeline, regular inspection of the inhalation pipeline, screen and bottom valve to prevent blockage and increase the resistance to liquid flow.
4、By improving the strength and anti-abrasion of pump material, it can effectively reduce the erosion of pump by cavitation, so as to reduce the damage of pump by cavitation and prolong its service life. In the structural design of the pump, by adding an induction wheel in front of the impeller of the centrifugal pump can also improve the anti-cavitation performance.
Three, to prevent the fire pump motor overload
1, The pump should check whether the export valve is in a fully closed state before starting, in order to prevent the motor from burning out due to excessive starting current.
2、Correctly choose the matching motor with the pump performance parameters to prevent the motor power is too small and overload long time operation.
3、Check the power supply voltage and current of each phase according to the technical parameters of the motor to ensure the error is within 3%. Remove the motor, check the rotation flexibility of the gear box shaft assembly and pump impeller and induced wheel, drain the liquid to find out if there is any mechanical failure, etc.
Fourth, to prevent abnormal vibration and wear of the fire pump
1, The pump installation to be secure, to regularly check its solidity, especially the foot or back bolts, to prevent fasteners loose.
2、Strengthen monitoring by monitoring the vibration waveform when the pump is running, and regularly check and repair the wear between the impeller and the sealing ring to find and eliminate hidden problems in time.
