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The service life of a pump depends on regular inspections. The inspection process mainly involves assessing the pump’s condition based on its external operating performance, in order to identify any abnormalities in the pump. Most abnormalities are not irreversible damage to the water pump. If the fault can be diagnosed and repaired promptly, the water pump can return to normal operation. There are mainly five types of abnormalities in water pumps: abnormal noise, abnormal vibration, abnormal performance, abnormal temperature rise, and other abnormalities. Today, we will explain the abnormal noise, which is one of these five types of abnormalities. Abnormal noise mainly refers to loud or shrill noises generated during the operation of the water pump. This noise may not be sufficient to cause noise pollution in the environment, but it indicates an issue with the water pump system that requires prompt inspection. The causes of noise can be roughly summarized as follows: https://p3-sign.toutiaoimg.com/tos-cn-i-qvj2lq49k0/786557eedc1340bbb8515fccd833e41c~noop.image?_iz=58558&from=article.pc_detail&x-expires=1661829370&x-signature=4CBAHJZzurzrayN%2FmdK4iIPLwoQ%3D This situation of gas and liquid mixing together is common in vertical pumps, as the outlet of such pumps is usually not at the *highest point of the pump body. When exhaust gases are not discharged or when the system generates gases, these gases accumulate at the top of the pump housing. As the pump operates, the accumulated gases undergo periodic changes in pressure (volume), resulting in abnormal noise from the pump housing. In this case, it is necessary to completely drain the water pump. If the system generates gas, check the cause of gas generation to prevent it from occurring. Cavitation refers to the shock phenomenon that occurs when, during water pumping, the inlet pressure drops below the saturation vapor pressure, causing the water to vaporize. Water containing bubbles comes into contact with the impeller surface; after being pressurized by the impeller, the bubbles dissipate, and the water surrounding the bubbles quickly fills their former positions. It’s usually a high-frequency metallic knocking sound on the pump head side, like popcorn popping. Cavitation can be checked by manually reducing/closing the outlet valve of the water pump. When the valve is reduced in size/closed, the noise disappears significantly, indicating cavitation. Solving the cavitation problem is very troublesome. First, minimize the resistance in the intake pipe and appropriately increase the intake pressure. The friction of the pump body refers to the contact friction within the mechanical structure. Mostly, this is due to improper assembly of the impeller or pump casing, resulting in axial or radial contact; or there is no contact during assembly, but the axial distance is less than the bearing clearance. When the pump is operating, the impeller inlet is under negative pressure, resulting in axial displacement and friction. This friction noise is caused by periodic or continuous metal friction; it can be checked by turning it by hand after the machine is stopped. The maintenance method involves removing the water pump, reassembling the faulty components, reworking those with incorrect dimensions, and replacing the bearings if they are damaged. Foreign objects entering refers to situations where, during the installation or operation of a water pump, foreign objects get into the pump’s flow channels and come into contact with or strike the impeller. The noise is usually the sound of metal friction; when turning it manually after shutting it down, intermittent or continuous resistance can be felt. The repair method involves disassembling the water pump, removing foreign objects, and checking for damage to components such as the impeller and pump body. When the damage is severe, parts need to be replaced. Bearings can rust. On some small-capacity pumps, there are no bearings on the pump head side; instead, the motor bearings serve to position and support it, such as in models like CM and PT. Due to heavy loads, some large-capacity pumps are equipped with side bearings on the pump head. Regardless of where the bearing is located, the grease can fail; it will rust when exposed to water or moisture, and a rusty bearing can cause operating noise. To address the issue of bearing rust, it is necessary to disassemble the bearing area, replace the bearings, and check whether other parts are also rusted and need cleaning. Dry grinding of bearings is different from bearing rusting; in some environments, the bearing area remains dry at all times. However, due to high temperatures in the bearings or the failure to replenish lubricant regularly, there is a lack of lubrication, which leads to increased friction in the bearings, significant heat generation, and rotating noise. Externally, this is manifested as high frictional resistance when manually turning the pump shaft while it is stopped; in cases of severe wear, increased axial movement may occur, and in such situations the water pump needs to be disassembled to replace the bearings. Most fan-driven water pumps are air-cooled motors, with the fan blades being the main components for dissipating heat from the motor. When the fan cover is deformed or misaligned due to external forces, it may come into friction with the fan blades; or when the fan blades are misaligned, it may come into friction with the rear cover of the motor. No matter what kind of friction there is, noise will be abnormal. Most fan blades are made of plastic; therefore, although the noise frequency is high and continuous, the pitch of the noise isn’t sharp. When encountering such a problem, it is necessary to check the friction points and adjust the installation position of the fan cover or fan blades in order to eliminate the friction. https://p3-sign.toutiaoimg.com/tos-cn-i-qvj2lq49k0/02108de5abec473f86fa5121fa3f50d5~noop.image?_iz=58558&from=article.pc_detail&x-expires=1661829370&x-signature=EvxQZRf%2BDC1lIpBRPRu0kQ99Cqk%3D When the flow rate is too high, or if the system design is inadequate or if there are significant constrictions in the pipes, the water system can generate sharp noises at such points, similar to the high-speed flow and vibration of air passing through a whistle. This kind of noise occurs mostly in the water pump pipes, rather than on the water pump itself. This can be eliminated by reducing the flow rate or improving the reducing pipe. Air vibration, also known as air pocketing, occurs when the foundation on which the water pump is installed has low strength and is semi-enclosed, allowing a large amount of air to accumulate. When the water pump vibrates, the air in the foundation vibrates as well, similar to resonance, resulting in low noise. Grasping the pump or its base with your hands, or lifting the pump and separating it from the base, can reduce or eliminate noise. This procedure can be used to diagnose the cause of the noise. The solution is to adjust the basic structure, increase strength, or add openings to allow air to escape. Electromagnetic noise refers to the sharp whistling sound that occurs when a frequency converter is used to drive a water pump, due to incompatibility between the parameters of the frequency converter and the hardware of the pump motor. This does not indicate anything about the quality of a particular series of frequency converters or pump motors, nor does it mean that those products are incompatible with each other; it is simply a case of incompatibility in this specific combination. This noise can be diagnosed by starting the water pump at line frequency or by adjusting the carrier frequency (switching frequency) of the inverter. The solution is also to adjust the carrier frequency (switching frequency); this frequency is typically a parameter that can be set on the inverter, and there is an internal adjustment gradient – by changing to the next frequency value, it may be possible to eliminate the noise. Does a water pump make noise when it is operating normally? Of course there will be noise. Under normal operation, noise is generated by the friction of water flow inside the water pump, by the mechanical friction in the motor rotor, and by the airflow from the motor fan used for cooling. Of these three types of noise, the first two are negative feedback related to the system’s requirements; they are directly associated with the pump parameters and motor power specified by the system. The third type of noise arises from the need for proper motor cooling. To address this issue, the centrifugal pumps developed by RICITE feature optimized fan blades that help reduce wind noise, thereby effectively lowering the noise generated during pump operation. The service life of a pump depends on regular inspections. The inspection process mainly involves assessing the pump’s condition based on its external operating performance, in order to identify any abnormalities in the pump. Most abnormalities are not irreversible damage to the water pump. If the fault can be diagnosed and repaired promptly, the water pump can return to normal operation. There are mainly five types of abnormalities in water pumps: abnormal noise, abnormal vibration, abnormal performance, abnormal temperature rise, and other abnormalities. Today, we will explain the abnormal noise, which is one of these five types of abnormalities. Abnormal noise mainly refers to loud or shrill noises generated during the operation of the water pump. This noise may not be sufficient to cause noise pollution in the environment, but it indicates an issue with the water pump system that requires prompt inspection. The causes of noise can be roughly summarized as follows: https://p3-sign.toutiaoimg.com/tos-cn-i-qvj2lq49k0/786557eedc1340bbb8515fccd833e41c~noop.image?_iz=58558&from=article.pc_detail&x-expires=1661829370&x-signature=4CBAHJZzurzrayN%2FmdK4iIPLwoQ%3D This situation of gas and liquid mixing together is common in vertical pumps, as the outlet of such pumps is usually not at the *highest point of the pump body. When exhaust gases are not discharged or when the system generates gases, these gases accumulate at the top of the pump housing. As the pump operates, the accumulated gases undergo periodic changes in pressure (volume), resulting in abnormal noise from the pump housing. In this case, it is necessary to completely drain the water pump. If the system generates gas, check the cause of gas generation to prevent it from occurring. Cavitation refers to the shock phenomenon that occurs when, during water pumping, the inlet pressure drops below the saturation vapor pressure, causing the water to vaporize. Water containing bubbles comes into contact with the impeller surface; after being pressurized by the impeller, the bubbles dissipate, and the water surrounding the bubbles quickly fills their former positions. It’s usually a high-frequency metallic knocking sound on the pump head side, like popcorn popping. Cavitation can be checked by manually reducing/closing the outlet valve of the water pump. When the valve is reduced in size/closed, the noise disappears significantly, indicating cavitation. Solving the cavitation problem is very troublesome. First, minimize the resistance in the intake pipe and appropriately increase the intake pressure. The friction of the pump body refers to the contact friction within the mechanical structure. Mostly, this is due to improper assembly of the impeller or pump casing, resulting in axial or radial contact; or there is no contact during assembly, but the axial distance is less than the bearing clearance. When the pump is operating, the impeller inlet is under negative pressure, resulting in axial displacement and friction. This friction noise is caused by periodic or continuous metal friction; it can be checked by turning it by hand after the machine is stopped. The maintenance method involves removing the water pump, reassembling the faulty components, reworking those with incorrect dimensions, and replacing the bearings if they are damaged. Foreign objects entering refers to situations where, during the installation or operation of a water pump, foreign objects get into the pump’s flow channels and come into contact with or strike the impeller. The noise is usually the sound of metal friction; when turning it manually after shutting it down, intermittent or continuous resistance can be felt. The repair method involves disassembling the water pump, removing foreign objects, and checking for damage to components such as the impeller and pump body. When the damage is severe, parts need to be replaced. Bearings can rust. On some small-capacity pumps, there are no bearings on the pump head side; instead, the motor bearings serve to position and support it, such as in models like CM and PT. Due to heavy loads, some large-capacity pumps are equipped with side bearings on the pump head. Regardless of where the bearing is located, the grease can fail; it will rust when exposed to water or moisture, and a rusty bearing can cause operating noise. To address the issue of bearing rust, it is necessary to disassemble the bearing area, replace the bearings, and check whether other parts are also rusted and need cleaning. Dry grinding of bearings is different from bearing rusting; in some environments, the bearing area remains dry at all times. However, due to high temperatures in the bearings or the failure to replenish lubricant regularly, there is a lack of lubrication, which leads to increased friction in the bearings, significant heat generation, and rotating noise. Externally, this is manifested as high frictional resistance when manually turning the pump shaft while it is stopped; in cases of severe wear, increased axial movement may occur, and in such situations the water pump needs to be disassembled to replace the bearings. Most fan-driven water pumps are air-cooled motors, with the fan blades being the main components for dissipating heat from the motor. When the fan cover is deformed or misaligned due to external forces, it may come into friction with the fan blades; or when the fan blades are misaligned, it may come into friction with the rear cover of the motor. No matter what kind of friction there is, noise will be abnormal. Most fan blades are made of plastic; therefore, although the noise frequency is high and continuous, the pitch of the noise isn’t sharp. When encountering such a problem, it is necessary to check the friction points and adjust the installation position of the fan cover or fan blades in order to eliminate the friction. https://p3-sign.toutiaoimg.com/tos-cn-i-qvj2lq49k0/02108de5abec473f86fa5121fa3f50d5~noop.image?_iz=58558&from=article.pc_detail&x-expires=1661829370&x-signature=EvxQZRf%2BDC1lIpBRPRu0kQ99Cqk%3D When the flow rate is too high, or if the system design is inadequate or if there are significant constrictions in the pipes, the water system can generate sharp noises at such points, similar to the high-speed flow and vibration of air passing through a whistle. This kind of noise occurs mostly in the water pump pipes, rather than on the water pump itself. This can be eliminated by reducing the flow rate or improving the reducing pipe. Air vibration, also known as air pocketing, occurs when the foundation on which the water pump is installed has low strength and is semi-enclosed, allowing a large amount of air to accumulate. When the water pump vibrates, the air in the foundation vibrates as well, similar to resonance, resulting in low noise. Grasping the pump or its base with your hands, or lifting the pump and separating it from the base, can reduce or eliminate noise. This procedure can be used to diagnose the cause of the noise. The solution is to adjust the basic structure, increase strength, or add openings to allow air to escape. Electromagnetic noise refers to the sharp whistling sound that occurs when a frequency converter is used to drive a water pump, due to incompatibility between the parameters of the frequency converter and the hardware of the pump motor. This does not indicate anything about the quality of a particular series of frequency converters or pump motors, nor does it mean that those products are incompatible with each other; it is simply a case of incompatibility in this specific combination. This noise can be diagnosed by starting the water pump at line frequency or by adjusting the carrier frequency (switching frequency) of the inverter. The solution is also to adjust the carrier frequency (switching frequency); this frequency is typically a parameter that can be set on the inverter, and there is an internal adjustment gradient – by changing to the next frequency value, it may be possible to eliminate the noise. Does a water pump make noise when it is operating normally? Of course there will be noise. Under normal operation, noise is generated by the friction of water flow inside the water pump, by the mechanical friction in the motor rotor, and by the airflow from the motor fan used for cooling. Of these three types of noise, the first two are negative feedback related to the system’s requirements; they are directly associated with the pump parameters and motor power specified by the system. The third type of noise arises from the need for proper motor cooling. To address this issue, the centrifugal pumps developed by RICITE feature optimized fan blades that help reduce wind noise, thereby effectively lowering the noise generated during pump operation.