From used part assessment to processing and delivery, these are the key steps

When repairing coal mine spare parts, the biggest concern is failing to replace components that should be replaced, which leads to equipment failure shortly after going underground. Another common issue is unnecessary replacement of repairable parts, resulting in wasted costs. Repair work cannot rely merely on surface wear observation or subjective experience. Starting with inspection of used parts, Henan Shuangzhi determines solutions based on actual conditions before carrying out restoration, machining and inspection for delivery.

Taking sprocket assemblies and crusher shaft assemblies as examples, we focus on checking worn areas, critical dimensions, main body conditions and fitting status. For heavily worn or obviously damaged sections, further measurement and evaluation will be performed to decide which components need replacement and which can be repaired. If original drawings are unavailable, we can conduct physical mapping based on the used part and verify relevant equipment and matching information to support subsequent machining.

After inspection, a processing plan is formulated according to the wear level and matching requirements of the used parts. Used parts eligible for remanufacturing will be repaired accordingly. Components that cannot meet service requirements through partial repair will be replaced as needed. During plan formulation, critical dimensions and matching standards are verified to avoid installation problems caused by dimension mismatch.

Machining and restoration are then carried out following the plan and relevant process specifications. Special attention is paid to the machining quality of critical dimensions, working surfaces and mating areas. We ensure the restored dimensions and fits meet technical requirements instead of only restoring the appearance.

Once restoration is finished, critical dimensions, repaired areas, fits and assembly conditions are inspected in line with product types and technical specifications. Products requiring trial operation will be tested accordingly. After inspection, product model, quantity and matching accessories are double-checked to prepare for delivery.

From used-part inspection to final delivery, Henan Shuangzhi develops solutions based on the condition of old parts and strictly implements machining and inspection. We fully restore parts that can be repaired and replace components that must be changed in compliance with standards. Every procedure is evidence-based to ensure delivered products fit customers’ practical needs.