Crown block sheaves, located at the top of drilling rigs, are notoriously difficult to repair, making seal failures a significant challenge. One of the world’s largest drilling operators approached Clark Seals to address the high failure rates and installation issues affecting these critical components.

Through extensive on-site analysis, it was determined that improper installation was the primary cause of leakage. Seals were being removed with screwdrivers and installed with hammers, which damaged both the sheave and seal, leading to premature failure.

Clark Seals engineers tackled this issue by employing innovative sealing principles not previously available in the industry. They focused on optimizing seal installation and retention forces, conducting tests on both lubricated and dry seals. The team explored a range of variables, including seal tolerances, installation and removal forces, rubber and metal case thicknesses, and interference between the rubber outer diameter and the sheave bore. Additionally, custom elastomers were formulated to reduce strain and improve retention forces.