Core principle of melt pump maintenance: first investigate external working conditions before disassembling

Melt pumps belong to high-temperature and high-pressure precision measuring equipment, and blind disassembly should be avoided during maintenance. Priority should be given to investigating external operating conditions (temperature, feed, back pressure), confirming the presence of internal mechanical faults, and then implementing standardized disassembly and maintenance procedures to avoid human expansion of equipment damage.

1、 Fault diagnosis sequence: check layer by layer from outside to inside

The temperature system checks the temperature control accuracy of the pump body and supporting pipelines. If the temperature difference is too large, it will cause fluctuations in the viscosity of the melt, directly leading to pressure instability and other phenomena.

The upstream feeding system confirms that the plasticizing effect of the extruder is uniform, the material is free of bubbles, and the feeding is continuous and stable; Check for issues such as clogged screen changers and sudden increase in filter pressure difference.

Check for carbon buildup in the downstream back pressure condition, abnormal valve operation, and sudden changes in pipeline resistance.

Internal mechanical faults (only carried out after the first three inspections show no abnormalities) include excessive gear wear and clearance, bearing failure, aging seals, and carbide accumulation and jamming.

2、 Standard maintenance six step process

Shutdown pre-treatment to cool down to a safe temperature range, empty the internal melt, soften and clean the residual materials, and mark and retain the pipeline and wiring positions.

Disassemble in an orderly manner in the order of cover plate → gear → bearing → seal; Record the assembly direction of the components and the original clearance data throughout the process, providing a basis for reassembly.

Precision testing uses micrometers and feeler gauges to detect gear meshing surfaces, shaft diameter tolerances, bearing clearances, and end face clearances, in order to determine component repair or replacement. Minor scratches can be polished, and blind polishing of core precision components is prohibited.

Cleaning and repairing use high-temperature calcination combined with solvent immersion to remove carbides; Replace aging seals, as well as out of tolerance gears and bearings; If wear-resistant coating strengthening treatment is required, corresponding technical qualifications must be obtained before implementation.

Apply high-temperature lubricating grease to the precise assembly of motion parts; The bolts are tightened using diagonal segmented fastening technology; Strictly control the end face clearance (conventional control 0.1-0.3mm); Manual turning inspection to confirm no jamming phenomenon.

Performance testing: no-load temperature rise, gradually increase pressure operation, monitor the stability of outlet pressure, flow accuracy, and whether there is leakage in the seal. Only when all indicators meet the standards can it be put into production use.

3、 Key risk warning

The pump body is stuck and cannot be forcibly started. Insufficient preheating, foreign objects getting stuck, and thermal expansion interference can all cause the melt pump to lock up. Forcefully starting can cause irreversible expansion damage.

It is recommended to return the shell to the factory for repair. If there are cracks in the shell, severe deformation of the shell, progressive fatigue damage to the components, or if the accuracy cannot be restored after non professional repair, it is necessary to send it back to a professional manufacturer for repair.

Daily maintenance recommendations include checking the oil level, temperature, and pressure difference parameters on a daily basis; Replace lubricating oil and clean filters every week; Disassemble and inspect the gap between components every year; Pre filtering should be done at the raw material end to prevent metal impurities from entering the pump body.

Reminder: The melt pump is a high-temperature and high-pressure precision component. If there are no specialized tools, measuring tools, or original technical parameters, it is recommended to contact the equipment manufacturer or certified service provider for maintenance work to prevent permanent loss of equipment accuracy.

Email: sale@meltpump.com

WhatsApp: +86 158 3833 1071

Any questions about our products, please feel free to contact us! We promise you high-end products and first-class service.Look forward to our cooperation!!!