Screw Conveyor Wear Management in EPB TBMs: Liners, Flights and Factory-Direct Spares

Screw conveyors are the pressure-control heart of an EPB TBM, and also one of its fastest-wearing assemblies. In abrasive alluvial soils — increasingly common on metro expansions across South Asia, where high water tables demand stable face pressure — the screw shaft, flights and casing liners grind against sand, gravel and cobbles continuously. Wear concentrates at the last flights near the discharge gate, where muck velocity and differential pressure peak, so component life varies far more by ground condition than by machine hours.

That variability is why condition-based planning beats calendar-based replacement. Inspect outer flight edges, shaft diameter at the discharge zone and liner thickness at each ring change, and log the trend against actual excavation. Hardfaced or tungsten-carbide-overlaid flights and replaceable wear-resistant liners let you restore geometry without scrapping the whole shaft. The goal is to swap consumables during a scheduled cutterhead or segment-logistics stop, not to lose days to a seized or holed screw in water-bearing ground.

Sourcing matters as much as maintenance. OUSUN, based in Deyang, Sichuan — China's largest TBM industrial cluster — manufactures screw conveyor shafts, flights, liners, seals and hydraulic/electrical spares as a factory-direct supplier, with interchangeable parts suited to refurbishment programmes and cost-sensitive machine fleets. Typical spare lead time runs about 2-4 weeks, which is short enough to keep a planned wear-replacement window realistic. For buyers, the takeaway is simple: treat the screw conveyor as a scheduled consumable, keep critical liners and flights in stock, and choose a supplier whose lead time fits your ring-build cycle.

Contact: [email protected] | tunnel-boring.com