Preparations required before starting a horizontal multi-stage centrifugal pump

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Preparations required before starting a horizontal multi-stage centrifugal pump: 1. Before starting the horizontal multi-stage centrifugal pump, check whether the name, model, key properties of the lubricating oil, as well as the amount to be added, meet the requirements specified in the technical documents； Are the bearing lubrication system, sealing system, and cooling system in good condition? Are the oil and water pathways of the bearings unobstructed? ； Rotate the rotor of the pump 1–2 times to check for any friction or sticking ； Are there any objects that could interfere with rotation near the coupling or in areas such as belt guards? ； Are the foundation bolts of the pump, bearing housing, and motor loose? ； The valves or auxiliary devices in the pump’s operating system should be in the position that results in the lowest load when the pump is running; the outlet control valve should be closed ； For the intermittent operation vertical multi-stage centrifugal pump, check whether the rotation direction of the impeller is consistent with the designed direction. If it is not, the impeller must be brought to a complete stop first; only after adjusting the motor wiring can the pump be started again. 2. Before starting a horizontal multi-stage centrifugal pump, it is necessary to fill it with water first. Before the pump is started, the pump casing and the suction pipe must be filled with water, as the vacuum at the pump’s suction inlet cannot be created or maintained in the presence of air. 3. Before starting a horizontal multi-stage centrifugal pump, it is necessary to warm up the pump first. For pumps that transport high-temperature liquids, such as the boiler feed water pumps in power plants, the pump must be warmed up before starting the horizontal multi-stage centrifugal pump. This is because when the feed water pump starts, high-temperature feed water flows through the pump, causing the pump’s temperature to rise rapidly from room temperature to 100–200°C. This creates a temperature difference between the inside and outside of the pump as well as between its various components. If there isn’t enough time for heat transfer and no appropriate measures are taken to control the temperature rise, uneven expansion throughout the pump will occur, leading to deformation, wear, vibration, and even bearing failure in different parts of the pump.