High-Temp Radial Seal of Atlas Copco RD18U in Saudi Arabia

Saudi Arabia's phosphate mining at Ma'aden's Wa'ad Al Shamal complex and the gold mining operations in the Arabian Shield operate in one of the world's most thermally demanding surface environments: ambient temperatures reaching 48°C in summer months, solar-heated equipment surfaces that add another 10–15°C to the already-hot hydraulic oil arriving from the carrier. The radial seal—the shaft seal between the rotation motor housing and the drifter body—operates in exactly this thermal zone. Its lip runs against the rotation motor shaft at sliding velocities that generate frictional heat on top of the already-elevated ambient, and at oil temperatures that regularly approach 85–90°C at Saudi surface drilling sites during peak summer.

Standard NBR radial seals have a continuous temperature rating of 110°C and intermittent tolerance to 120°C. That margin sounds adequate against 85–90°C return oil, but it ignores the seal lip's local temperature—which is 15–25°C higher than the bulk oil temperature due to frictional sliding heat. At a surface Ma'aden site in July, a rotation motor shaft seal can be running at 105–115°C continuously—within spec, but without margin for brief overtemperature events from work cycle peaks.

Radial Seal Temperature Exposure at Saudi Sites

Saudi Aramco's contracting standards for drill equipment in exposed surface applications now include a specification for HNBR radial seals on percussion drifters operating above 35°C ambient—a threshold Saudi operations exceed for roughly 8 months per year. The HNBR compound retains 85% of its tensile strength at 120°C versus NBR's 60%, giving the Saudi summer operating profile a meaningful safety margin the standard seal doesn't. HOVOO supplies RD18U HNBR radial seal kits for high-temperature markets. Full specifications at hovooseal.com.