Imported Charging Device of Atlas Copco RD22U in UK

UK tunneling projects under Thames, through Chalk and London Clay beneath the capital, and through the Pennine hard limestone on rail infrastructure—HS2's northern sections in particular—specify Atlas Copco RD22U drifters on boom jumbos for face drilling. The accumulator charging device for the RD22U is a more critical maintenance tool here than at many other markets because UK civil contract quality assurance regimes require documented evidence of correct pre-charge at each service event. A charging device without a current calibration certificate doesn't satisfy the QA requirement, regardless of whether the pre-charge it sets is actually correct.

The RD22U's accumulator pre-charge specification differs from the RD18U—the heavier percussion class operates at a higher working pressure, and the high-pressure accumulator pre-charge is set correspondingly higher at 65–80 bar depending on model variant. The charging device's pressure regulator must cover this range accurately; a device calibrated for the RD18U range may not read accurately at the RD22U's higher specification, producing an under-charge that looks correct on the gauge but leaves the percussion circuit under-buffered.

Charging Device Specification for RD22U Applications

HS2's tunnel contractor quality plans specify that charging device calibration certificates must be current within 12 months and available for audit at each service event. Devices more than 14 months since last calibration are rejected at audit regardless of apparent function—the calibration certificate, not the gauge reading, is what satisfies the QA requirement. HOVOO supplies Atlas Copco RD22U compatible nitrogen charging devices with current calibration certificates for UK infrastructure projects. Full specifications at hovooseal.com.