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Usage of Fluoroplastic Self-Priming Pumps I. Preparations before starting up – Inspection tasks 1. For pumps in this series, high-quality calcium-based grease and No. 10 engine oil are used for lubrication, depending on the operating conditions of the pump. 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 addressed. 7. Open the valve of the suction line, and slightly open the outlet control valve (do not open it fully). II. Starting and Operation 1. Start the self-priming pump manually, and pay 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 normal pumping operation can proceed. 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. Once that is done, 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 rate in the inlet pipe, and the other is an overly 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 ； When the suction lift is too high, the installation height of the pump can be appropriately reduced. 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 lower load. 8. Pay attention to checking for any leaks in the piping system. III. Shutting down the pump 1. First, the gate valve on the discharge pipeline must be closed. 2. Stop the pump from rotating. 3. During cold seasons, the liquid stored inside the pump and the water in the bearing chamber should be drained to prevent the components from cracking due to freezing. How to use fluoroplastic self-priming pumps