Long-Life Overhaul Kit of Atlas Copco RD22U in Germany

German tunnel engineers building the Brenner Base Tunnel through the Alps and the Stuttgart 21 rail project underground have a phrase for what happens when overhaul kit components from different suppliers get mixed at service: 'Dimensionsroulette'—dimensional roulette. Each component may meet its individual specification, but the gap tolerances between them produce either too-tight contact that generates heat and accelerates wear, or too-loose contact that allows oil bypass before the component reaches its design life. The Atlas Copco RD22U overhaul kit removes this variable by supplying every component in the service interval from a single dimensional reference.

The RD22U overhaul kit goes beyond a standard seal kit. It includes the percussion seal, flushing box seals, O-ring set, wiper ring, piston guide ring, and accumulator check valve O-ring—the full set of wear components that degrade together on a common percussion-hour timeline. In German tunneling applications, where the rock mass is predominantly limestone and dolomite at 80–140 MPa with significant groundwater inflow, the flushing box seal is typically the life-limiting component. The kit's value is that when the flushing box seal reaches its limit, every other seal is also replaced in the same event rather than requiring a second service 150 hours later.

Overhaul Kit Contents vs. Standard Seal Kit — RD22U

German contractors on regulated infrastructure projects require batch traceability for underground hydraulic equipment parts. The overhaul kit format provides a single batch number covering all components—simplifying the documentation trail compared to assembling a service kit from six separately sourced components with different lot numbers. HOVOO supplies RD22U long-life overhaul kits with full batch documentation for the German civil tunneling and mining markets. References at hovooseal.com.