[Q&A Question 332] 2017.12.16

Performing pre-start rotation of the pump is to check whether the pump is stuck or engaged in any way； In terms of safe operation, during pump shutdown, the lubricating oil film on the various friction surfaces disappears, and foreign objects may also get in, causing changes in the relative positions of the moving parts. Starting the pump suddenly can likely lead to friction, collisions, and jamming between the components, thereby damaging the pump’s parts

Performing pre-start rotation of the pump is to check whether the pump is stuck or engaged in any way； In terms of safe operation, during pump shutdown, the lubricating oil film on the various friction surfaces disappears, and foreign objects may also get in, causing changes in the relative positions of the moving parts. Starting the pump suddenly can likely lead to friction, collisions, and jamming between the components, thereby damaging the pump’s parts

Ensure that the pump shaft does not deform; excessive resistance when turning the shaft can lead to high starting currents, which may damage the motor.

Answer: Whether it is a centrifugal pump, a reciprocating pump or other types of pumps, as well as piston compressors, centrifugal compressors, blowers or other types of pneumatic compressors, when they are restarted after being shut down for an extended period of time, it is necessary to turn the machine by hand several times before starting it up using its prime mover (such as an electric motor or steam turbine). This act of turning the machine by hand is what is referred to as \"cranking\". During periods when the machine is not in operation, the lubricating oil film on the various friction surfaces gradually disappears; moreover, foreign objects may enter or components may become loose, which alters the relative positions of the moving parts. If the machine is started up at high speed under such conditions, it will inevitably lead to rapid wear of the components, as well as collisions and jams. All of these can cause destructive equipment failures, which must be prevented; moreover, turning the shaft can reduce starting inertia and the amount of rotation required during startup. Turning the machine is a measure to prevent such accidents. During this process, lubricating oil is delivered to various friction surfaces; for example, as the oil ring rotates along with the shaft, it carries oil to the bearings. This allows any potential collisions or jams within the machine to be detected in a timely manner. Therefore, turning the machine is of great importance for ensuring the safe operation of the machinery.

Check for any sticking, whether there are foreign objects inside the pump, and whether the shaft is bent or deformed, in order to prevent damage to the equipment after it starts operating

Rotate the pump to check whether it operates smoothly. Even out the lubricating oil.

Whether it is a centrifugal pump, a reciprocating pump or other types of pumps, as well as piston compressors, centrifugal compressors and blowers or other types of pneumatic compressors, when they are restarted after being shut down for an extended period of time, it is necessary to perform shaft turning before starting them up using their prime mover (such as an electric motor or a steam turbine). By \"shaft turning\", it means manually rotating the machine several times. During periods when the machine is not in operation, the lubricating oil film on the various friction surfaces gradually disappears; moreover, foreign objects may enter or components may become loose, which alters the relative positions of the moving parts. If the machine is started up at high speed under such conditions, it will inevitably lead to rapid wear of the components, as well as collisions and jams. All of these can cause destructive equipment failures, which must be prevented; moreover, turning the shaft can reduce starting inertia and the amount of rotation required during startup. Turning the machine is a measure to prevent such accidents. During this process, lubricating oil is delivered to various friction surfaces; for example, as the oil ring rotates along with the shaft, it carries oil to the bearings. This allows any potential collisions or jams within the machine to be detected in a timely manner. Therefore, turning the machine is of great importance for ensuring the safe operation of the machinery.

Whether it is a centrifugal pump, a reciprocating pump or other types of pumps, as well as piston compressors, centrifugal compressors and blowers or other types of pneumatic compressors, when they are restarted after being shut down for an extended period of time, it is necessary to perform shaft turning before starting them up using their prime mover (such as an electric motor or a steam turbine). By \"shaft turning\", it means manually rotating the machine several times. During periods when the machine is not in operation, the lubricating oil film on the various friction surfaces gradually disappears; moreover, foreign objects may enter or components may become loose, which alters the relative positions of the moving parts. If the machine is started up at high speed under such conditions, it will inevitably lead to rapid wear of the components, as well as collisions and jams. All of these can cause destructive equipment failures, which must be prevented; moreover, turning the shaft can reduce starting inertia and the amount of rotation required during startup. Turning the machine is a measure to prevent such accidents. During this process, lubricating oil is delivered to various friction surfaces; for example, as the oil ring rotates along with the shaft, it carries oil to the bearings. This allows any potential collisions or jams within the machine to be detected in a timely manner. Therefore, turning the machine is of great importance for ensuring the safe operation of the machinery.

During the shutdown period of the pump, the lubricating oil film on the various friction surfaces gradually disappears; moreover, foreign objects may enter or components may become loose, which alters the relative positions of the moving parts. If the machine is started to operate at high speed in such a condition, it will inevitably lead to rapid wear of the components, as well as collisions and jams. All of these can cause destructive equipment failures, which must be prevented; moreover, turning the shaft can reduce starting inertia and the amount of rotation required during startup. Turning the machine is a measure to prevent such accidents. During this process, lubricating oil is delivered to various friction surfaces; for example, as the oil ring rotates along with the shaft, it carries oil to the bearings. This allows any potential collisions or jams within the machine to be detected in a timely manner. Therefore, turning the machine is of great importance for ensuring the safe operation of the machinery.

To prevent jamming during pump operation and ensure long-term operation. Prevent high vibration speeds and temperatures at the connected and unconnected ends of the pump during operation