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Correct installation method for self-priming, clog-free sewage pumps: 1. For pumps with direct coupling, when transmitting power from the motor to the pump, attention should be paid to the coaxiality between the pump shaft and the motor’s output shaft； The accuracy of the installation of self-priming, clog-free sewage pumps has a significant impact on the smooth operation and service life of these pumps; therefore, careful and thorough installation and adjustment are necessary. 2. The coupling of a coupled pump must be securely fastened with nuts, and the lock nuts should also be tightened to prevent the nuts from loosening; otherwise, it can lead to the impeller shifting, resulting in mechanical failures. 3. To maintain a certain amount of liquid within the pump chamber, thereby achieving better self-priming capability and preventing dry friction of the mechanical seal, it is necessary to have the pump inlet at a higher level than the centerline of the pump shaft. 4. Notes on the installation of the suction pipeline: ① The installation height of the suction inlet shall not exceed 5 meters. Where conditions permit, it should be as low as possible below the lowest water level in the tank, and the length of the suction pipe should be minimized with as few elbows as possible. This helps to reduce the self-priming time and improve the self-priming capability. ②Valves, flanges, and other components in the suction line must be kept free from air leaks or liquid seepage; in other words, there should be no air leaks in the suction line. ③It is necessary to prevent excessive intake of solids and other debris into the pump chamber; therefore, a filter should be installed on the suction pipeline. The effective flow area of the filter should be 2-3 times that of the suction pipe’s cross-section, and the filter should be inspected regularly. ④The intake and exhaust pipelines should have their own supports; the pump body itself must not bear the load of the pipelines. 5. When installing the pump, the static grounding resistance of the pump and its piping must meet the specified requirements. 6. During installation, it is necessary to carefully check whether there are any stones, iron sand, or other debris in the pump casing and pipelines. 7. Adjust the installation clearance and coaxiality of the pump coupling and the motor coupling; the allowable deviation for misalignment is 0.1 millimeters. The height difference between the pump shaft and the motor shaft can be adjusted by placing copper or iron sheets under the feet. 8. After the unit has been operating for 3–4 hours, conduct a final inspection; if no abnormalities are detected, it is considered that the installation is complete. During the trial operation, the temperature of the bearings should be monitored, with the temperature of the bearing housings not exceeding 70°C. 9. The cooling water connections provided in the bearing housing of this pump, which are equipped with cooling chambers, are designed for rubber hoses or plastic tubes with an inner diameter of Φ12; the thread size is M12×1.75. 10. If a check valve is installed on the pump’s outlet pipeline and this prevents the pump from discharging gas properly during self-priming, an exhaust tube and valve should be added at the pump’s outlet. Operating Instructions for Self-Priming Non-Clogging Sewage Pumps I. Preparations before starting the self-priming non-clogging sewage pump include inspection tasks. 1. Depending on the operating conditions of the pump, high-quality calcium-based grease or No. 10 engine oil is used for lubrication. For pumps lubricated with grease, it is necessary to regularly add grease to the bearing housing; for pumps lubricated with oil, the oil level should be topped up if it is insufficient. 2. Check whether the liquid level inside the pump casing is above the upper edge of the impeller. If it is not sufficient, liquid can be added directly into the pump through the filling port on the casing. The pump should not be started when the liquid level is low, as this will prevent it from functioning properly and may also damage the mechanical seal. 3. Check whether there is any jamming or collision in the rotating parts of the pump. 4. Check whether the footings of the pump body and the nuts at all connection points are loose. 5. Check the coaxiality and parallelism between the pump shaft and the motor shaft. 6. Check whether the inlet pipeline is leaking air; if there is a leak, it must be fixed. 7. Open the valve of the suction line, and slightly open the outlet control valve (do not open it fully). II. Starting and Operation of the Self-priming Non-clogging Sewage Pump 1. Start the self-priming pump, paying attention to whether the rotation direction of the pump shaft is correct. 2. Pay attention to any abnormal noises or vibrations during rotation. 3. Pay attention to the readings on the pressure gauge and vacuum gauge. Once these readings stabilize after some fluctuation following startup, it indicates that liquid has filled the pump and it is now in normal operation mode. 4. During the self-priming process before the pump starts normal pumping operation, special attention should be paid to the increase in water temperature inside the pump. If this process takes too long and the water temperature inside the pump becomes too high, the pump should be stopped to investigate the cause. 5. If the temperature of the liquid inside the pump is too high, causing difficulties in self-priming, the pump can be stopped temporarily. The liquid in the discharge pipeline can be allowed to flow back into the pump, or liquid can be directly added to the pump at the reservoir port, in order to lower the temperature of the liquid inside the pump; after that, the pump can be restarted. 6. If the pump experiences severe vibration and noise during operation, it may be due to cavitation. There are two reasons for cavitation: one is an excessive flow velocity in the inlet pipe, and the other is an excessively high suction head. When the flow rate is too high, the outlet control valve can be adjusted to increase the pressure gauge reading; if there is a blockage in the inlet pipeline, it should be removed promptly. If the suction lift is too high, the installation height of the pump can be reduced appropriately. 7. When the pump stops operating for some reason during operation and needs to be restarted, the outlet control valve should be left slightly open (not fully closed). This facilitates the expulsion of gas from the outlet during the self-priming process, while also ensuring that the pump starts under a lighter load. 8. Pay attention to checking for any leaks in the piping system.