I. Preparations Before Startup

a. Pre-Startup Inspection

1. Do the lubricant’s name, model, key performance characteristics, and filling quantity meet the requirements specified in the technical documentation?

2. Are the bearing lubrication system, sealing system, and cooling system in good condition? Are the oil and water passages for the bearings clear and unobstructed?

3. Manually turn the pump rotor 1–2 revolutions to check for any friction or jamming issues.

4. Are there any obstructions—such as debris—near the coupling or in areas like belt guards that could impede rotation?

5. Are the foundation anchor bolts for the pump, bearing housing, and motor loose?

6. All valves and auxiliary devices in the pump system should be set to their positions that minimize load during pump operation; the outlet control valve should be closed.

7. Briefly activate the pump and check whether the impeller’s rotation direction matches the designed direction. If it doesn’t, you must first ensure the impeller has completely stopped before adjusting the motor wiring—and only then can you restart the pump.

b. Fill with water

Before starting the pump, the pump casing and suction pipe must first be filled with water, as air present would prevent the formation and maintenance of a vacuum at the pump inlet.

c. Warm pump

Pumps that convey high-temperature liquids, such as boiler feedwater pumps in power plants, must be warmed up before startup. This is because, during startup, the hot feedwater flows through the pump, causing the pump body temperature to rapidly rise from ambient levels to 100–200°C. Such a sudden temperature increase creates significant thermal gradients between the pump’s interior and exterior, as well as among its various components. Without sufficient heat-transfer time or proper measures to control the rate of temperature rise, this uneven expansion can lead to deformation, wear, vibration, and even bearing seizure incidents throughout the pump.