High-Pressure Cylinder of Atlas Copco RD22U in Russia

Norilsk Nickel's sulfide ore operations in Siberia and the Polyus gold operations at Natalka in Magadan Oblast are among the world's most logistically isolated mine sites. The RD22U percussion cylinder at these locations isn't replaced on a preventive schedule—it gets inspected when symptoms appear, and if the inspection finds it serviceable, it stays in. That approach works only if the cylinder bore surface is measured accurately rather than assessed visually. A cylinder bore that looks clean under a headlamp can have 0.12 mm of wear—still within replacement limit—or 0.18 mm of wear—past it—and the two conditions look identical without a bore gauge. At remote Russian sites where the next cylinder is 3–5 days away by air freight, the distinction is worth 3 minutes and a bore gauge.

The RD22U cylinder is the pressure housing for the percussion bore, valve block mounting face, and accumulator port. Its internal bore is honed to Ra 0.4–0.8 μm to support the oil film between the piston guide and the bore wall. In Russian operations where hydraulic oil cleanliness runs above ISO 17/15/12—common at sites where oil changes lag the schedule—abrasive particle circulation scores the bore longitudinally. Those score lines create pathways for seal lip bypass that cut effective percussion pressure before any external leak is visible.

Cylinder Bore Condition and Russian Site Decision Logic

Siberian operations at Norilsk have standardized on pre-ordering a cylinder when bore measurement crosses 0.10 mm—two inspection cycles before the replacement limit—to absorb the logistics lead time without a production stoppage. The cylinder sits on the shelf; if the next inspection shows 0.13 mm, it goes in immediately. If the bore is holding at 0.11 mm, the ordered cylinder waits for the next inspection. HOVOO supplies RD22U high-pressure cylinders for Russian remote operations with documented bore dimensions. References at hovooseal.com.