How to reduce mechanical wear of horizontal centrifugal pump

Horizontal centrifugal pumps are widely used in petrochemical, electric power, water supply and drainage, metallurgy and other industrial fields, and are key equipment in fluid conveying systems. In the long-term operation process, mechanical wear is one of the main factors affecting the life, efficiency and stability of pump equipment. Through systematic technical measures and scientific management methods, the mechanical wear of the pump can be effectively reduced, and the operating reliability and equipment service life can be improved.

Optimize structural design
The structural design of the horizontal centrifugal pump is directly related to its stress state and wear distribution. Reasonable design of the gap between the impeller and the pump casing, the bearing support form, the shaft seal structure, etc. can effectively reduce the wear caused by the relative movement between the components.
Using a balanced impeller or setting a balancing hole can reduce the axial thrust, reduce the force on the thrust bearing, and extend the bearing life. The higher the straightness of the shaft and the accuracy of the bearing alignment, the less likely the shaft will deflect during operation, which can effectively avoid abnormal wear of the bearing and the sealing part.

Reasonable selection of materials
The characteristics of the medium under different working conditions will directly affect the wear condition of the pump components. For occasions where solid particles or corrosive media are transported, materials with excellent wear resistance and corrosion resistance should be selected, such as high chromium alloy, stainless steel, tungsten carbide spray or ceramic composite materials.
The impeller, pump casing and mouth ring and other flow-through parts should be selected according to the properties of the medium. The sealing end face material can be selected from low-friction, high-hardness materials such as silicon carbide and carbon graphite to improve wear resistance. For parts such as sleeves and bearings, fatigue-resistant and impact-resistant materials should also be considered to resist the wear stress caused by high-frequency vibration and load fluctuations.

Improve the performance of the lubrication system
Lubrication is one of the most direct and effective means to reduce friction and wear. Whether the bearing is fully lubricated and whether the lubricant is matched has a decisive influence on the service life of the pump shaft rotating parts.
The use of high-quality grease or lubricating oil to ensure good oil film strength and oxidation resistance within the operating temperature range is the basic guarantee. For sliding bearings or high-speed rolling bearings, a forced circulation lubrication system can be configured to maintain a stable oil temperature through an oil cooler, effectively inhibiting dry friction wear caused by oil film rupture.
Regularly replacing lubricating oil, cleaning the oil circuit, and preventing impurities from depositing in the oil are necessary measures to maintain the long-term effective operation of the lubrication system.

Control the stability of operating conditions
The instability of operating conditions is a hidden cause of increased mechanical wear. The pump should operate as close to the design operating point (BEP) as possible to avoid long-term operation at a deviation from the operating point (low flow, high head).
Frequent start-stop, idling, forced evacuation and other operating behaviors can easily cause impact loads on bearings, impellers, shaft seals and other components, resulting in increased fatigue wear. By installing a frequency converter to achieve soft start and steady-state speed control, mechanical shock can be significantly reduced and operating stability can be improved.
If the fluid contains hard particles such as sand, gravel, and impurities, a filter or sand settling device should be installed at the pump inlet to prevent solid particles from directly scouring the inner surface of the pump body, causing erosion and wear.

Strengthen the management of the sealing system
If the lubrication and cooling conditions of the sealing device, especially the mechanical seal area, are not properly controlled, dry friction and heating of the end face will occur, resulting in cracks, carbonization or sintering of the end face material, which will cause seal failure and severe wear of the sleeve.
The lubricating fluid in the sealing cavity should be kept clean and the flow rate should be stable, and the cooling pipeline should be unobstructed. Double-end seals should be equipped with a reliable sealing liquid replenishment system and pressure regulating device to prevent cavitation from impacting the sealing surface.
After the seal fails, it should be repaired and replaced in time, and it should not be operated with a fault for a long time to prevent a small fault from expanding into a large wear.