What are the maintenance measures for mining multistage centrifugal pumps?

In order to ensure that the mining multistage centrifugal pumps can operate safely and well for a long time, it is necessary not only to select it reasonably but also to use it reasonably and maintain it correctly. In order to ensure that the mining multistage centrifugal pumps can work normally at any time and under any circumstances, daily maintenance and mandatory maintenance must be done well.

• Main contents of daily maintenance:

The daily maintenance work of mining multistage centrifugal pump mainly includes the following points:

1. The outlet pressure, current, bearing temperature rise and vibration of the pump should be checked regularly, and the operation record and equipment inspection record should be filled in on time.
2. The temperature and water volume of cooling water should be checked regularly and recorded.
3. Check whether the oil cup is full of lubricating oil regularly, and add or replace the lubricating oil according to the equipment lubrication requirements.
4. The pump must be turned 3 to 5 times within 8 hours of shutdown, and records should be kept.
5. Check whether there is leakage at the dynamic and static sealing points of equipment and process pipelines.
6. Regularly (every time the operator inspects on site), check whether the main engine is running smoothly, whether there is any abnormal sound, whether the connecting bolts and anchor bolts of each part are loose, and keep records of daily equipment inspection and maintenance.
7. Deal with various equipment defects found in a timely manner and keep records, and report those that cannot be handled in a timely manner.
8. Clean the equipment well.

• Mandatory maintenance of mining multistage centrifugal pumps

In addition to regular maintenance work, centrifugal pumps also need mandatory maintenance. Mandatory maintenance means that after the centrifugal pump reaches the maintenance operation time of each level, the pump is forced to stop, and a comprehensive inspection is carried out according to the maintenance content of each level, the technical data is tested, and the operation record is kept. Mandatory maintenance of centrifugal pumps is generally divided into three levels of mandatory maintenance, which are:

First-level maintenance: the centrifugal pump runs for 1000h±24h;

Second-level maintenance: the centrifugal pump runs for 3000h±24h;

Third-level maintenance: the centrifugal pump runs for 10000h±24h.

When the bearing of a single-stage centrifugal pump is replaced, it is considered an overhaul. Because the number of bearing replacements is generally large, the highest maintenance level of a single-stage centrifugal pump is set as second-level maintenance. Most of the third-level maintenance is for multi-stage centrifugal pumps. Although the time specified for the third-level maintenance varies from place to place, the maintenance content is roughly the same.

• Contents of first-level maintenance of mining multistage centrifugal pumps

In addition to completing regular maintenance, the first-level maintenance of mining multistage centrifugal pumps also requires the following work:

• Check and adjust the front and rear sealing packings to ensure that they are not heated, leaking excessively, and that the sleeve and gland are not worn.
• Check the end cover screws, pump casing tightening screws, base and bearing bracket screws to ensure that the slide buckles are not loose.
• Check the coupling to ensure that the screws are evenly stressed and have consistent tightness.
• Check the pressure gauge to ensure that it is flexible and accurate without loosening or leaking.
• Clean the filter to ensure that it is clean and unobstructed.

• Contents of second-level maintenance of mining multistage centrifugal pumps

In addition to completing the first-level maintenance work, the following work must be performed:

• Clean the front and rear bearing boxes, and check or replace the engine oil and grease.
• Check the wear of the sealing packings and replace them if necessary.
• Check the appearance and concentricity of the coupling.
• Check, clean and replace the pump bearings, and add butter.
• Check the wear of the sleeve seal and replace it if necessary.
• Check the wear of the balance disc and balance ring, and replace them if the wear exceeds the required standard.
• Check that the pump shaft movement is within the specified range.

• Level 3 maintenance content of mining multistage centrifugal pump

In addition to completing the level 1 and level 2 maintenance content, the following work content should also be completed:

• Check the front and rear bearings and measure the bearing clearance.
• Check and clean the impeller, guide vane, guide vane fixing screws and pump casing.
• Measure the gap between the impeller and the sealing ring and the matching of the sealing ring and the guide vane.
• Check and correct the matching of the pump shaft and the coupling and the pump shaft.
• Check the amount of leakage between the balance plate and the balance ring.
• Check and adjust the concentricity of the coupling.
• Perform static balance test on the impeller and balance plate.
• Measure the vibration of the motor and pump.