Suggestions on Regular Maintenance and Replacement Cycle of Vulnerable Parts for

RCB high-temperature hot oil pump, as a key equipment for transporting high-temperature hot oil, is widely used in industries such as chemical, manufacturing, and food. To ensure its long-term stable operation, reduce failure rate, and extend service life, it is necessary to develop a correct regular maintenance plan and replacement cycle for vulnerable parts. The following suggestions are proposed from four aspects: maintenance cycle, maintenance content, replacement cycle of vulnerable parts, and operating standards.

1、 Regular maintenance cycle

1. Daily inspection

Daily visual inspection of the hot oil pump is required, mainly focusing on whether the pump body, pipelines, and joints are loose or leaking. Rotate the pump shaft by hand to confirm its flexibility. At the same time, check whether the lubricating oil level is at the center line of the oil gauge. If the level is insufficient, it should be replenished in a timely manner. In addition, it is necessary to observe the temperature of the cooling water return water, which is warm but not hot to the touch, to avoid the return water carrying black oil or steam.

2. Weekly inspection

Every week, the sealed quench water hose of the hot oil pump needs to be inspected to confirm that it is not detached or damaged; Check if the sealing oil pressure is stable. If the pressure gradually increases, analyze the cause and handle it in a timely manner; Clean the filter to prevent impurities from clogging and affecting the performance of the pump body.

3. Monthly maintenance

Every month, a comprehensive inspection of the hot oil pump is required, including cleaning the cooling system and removing scale from the water jacket and pipes; Check the corrosion of components such as impellers, pump bodies, and balance pipes; Lubricate and maintain the bearings to ensure smooth operation. In addition, it is necessary to check the alignment of the coupling to avoid displacement of the pump shaft center due to thermal expansion.

4. Annual major overhaul

Every year, the hot oil pump needs to undergo major repairs, including finding bends in the main shaft, replacing worn parts, and inspecting the sealing auxiliary system. During the overhaul period, the cooling system needs to be completely cleared and water pipes replaced as needed; Conduct a comprehensive inspection of the pump body and repair any sand holes or cracks; Disassemble and inspect the mechanical seal, and replace any aging or damaged seals.

2、 Maintenance content

1. Maintenance of cooling system

The cooling system is crucial for the normal operation of the hot oil pump. During maintenance, it is necessary to check the cooling water flow rate and ensure that the return pipe temperature is appropriate; Clean the cooler to prevent impurities from blocking and affecting the cooling effect; Check the flow rate of rapid cooling water or steam on the back of the seal to determine if it can remove heat and prevent seal failure.

2. Sealing system maintenance

Mechanical seal is one of the easily damaged components of hot oil pump. During maintenance, it is necessary to check whether the working surface of the sealing dynamic and static rings is worn. If the wear is severe, it should be replaced in a timely manner; Check the sealing auxiliary system, such as whether the external flushing pressure and flow rate meet the requirements, and whether the sealing oil can prevent heat transfer from the pump chamber; Perform a primary inspection on the serial seal to prevent seal failure due to poor assembly quality.

3. Bearing maintenance

Bearings are one of the core components of a hot oil pump. During maintenance, it is necessary to check whether the bearing temperature is stable. If the temperature on the outer surface of the bearing box rises to a relatively good level, it should be dealt with in a timely manner; Check the lubrication condition of the bearings and ensure that the lubricating oil is clean and free of impurities; Replace severely worn bearings to extend the service life of the pump shaft.

3、 Replacement cycle of vulnerable parts

1. Mechanical seal

The replacement cycle of mechanical seals needs to be determined based on actual operating conditions. If the pressure fluctuation in the sealed chamber is large or the medium contains impurities, the replacement cycle needs to be shortened; If the sealing performance is stable, the replacement cycle can be appropriately extended. It is generally recommended to disassemble and inspect the mechanical seal annually, and decide whether to replace it based on the wear condition.

2. Bearings

The replacement cycle of bearings should be determined based on their wear condition. If the wear on the inner surface of the shaft or bearing is found to be close to the thickness of the hardened layer, the shaft can be polished and reused, only replacing the bearing; If the bearing is severely worn or produces abnormal noise, it needs to be replaced immediately. It is generally recommended to conduct a complete inspection of the bearings every two years and decide whether to replace them based on the actual situation.

3. Impeller

The replacement cycle of the impeller needs to be determined based on its corrosion condition. If there is erosion or cavitation on the surface flow channel of the impeller, it should be replaced in a timely manner; If the clearance between the impeller mouth ring and the sealing ring is too large, which affects the performance of the pump body, the impeller also needs to be replaced. It is generally recommended to conduct a comprehensive inspection of the impeller every three years and decide whether to replace it based on the actual situation.

4、 Operating standards

1. Preheating and start-up

Preheating is required before starting the hot oil pump, and the heating rate should be controlled within the correct range to avoid deformation of the pump body or seal failure due to rapid temperature rise. During the preheating process, regular turning is required to ensure flexible rotation of the pump shaft. When starting, it is necessary to first turn on the cooling water system, then turn on the oil sealing system, and slowly open the inlet and outlet valves to avoid sudden pressure rise and damage to the pump body.

2. Operation monitoring

During operation, it is necessary to closely monitor the parameters of the hot oil pump, such as inlet and outlet pressure, flow rate, temperature, etc. If any abnormal parameters or leakage, abnormal noise or other phenomena are found, the machine should be stopped immediately for inspection and handling. At the same time, it is necessary to regularly record operational data to provide reference for subsequent maintenance.

3. Shutdown and maintenance

Before shutting down, it is necessary to close the inlet and outlet valves first, and then close the inlet valve and cooling water system. After shutdown, the pump body needs to be cleaned and maintained to remove internal impurities and oil stains; Inspect and replace vulnerable parts; Clean and lubricate the sealing system to ensure it is in good condition.