Split Oil Seals & Open-Type Shaft Seals

Split oil seals—also called open-type oil seals, segmented shaft seals or clamped rotary seals—are designed for equipment where removing the shaft to install a one-piece seal is impractical or prohibitively expensive. The seal body is split along one side or hinged so it can be opened, wrapped around the shaft and closed in the housing bore. Once installed, the joint is locked by an internal tongue-and-groove or interlocking rib that restores circumferential sealing integrity. Split seals are widely used on large pumps, mixers, turbines, gearboxes, paper machine rolls and mining equipment. The primary advantage of a split oil seal is maintenance access. In a conventional solid seal replacement, the shaft, pulley, coupling and sometimes bearings must be removed to slide a new seal into place. A split seal reduces this downtime from hours or days to minutes. The trade-off is a slightly more complex design and higher unit cost compared to a standard TG4 seal, but the total cost of ownership is often far lower when downtime, labor and lost production are included. Our split seals are available in two main constructions. All-rubber split seals use a flexible NBR or FKM body without a metal case, making them highly conformable and easy to install in worn or non-standard housings. Metal-cased split seals combine a segmented steel shell with a rubber sealing lip for applications requiring higher structural rigidity, pressure retention and dimensional stability. Both designs use a garter spring or internal energizer to maintain lip-to-shaft contact after assembly. Split seals rely on precise joint design to prevent leakage at the split line. We use interlocking profiles, adhesive bonding at the joint or clamping bands depending on the pressure, speed and size. For critical services, we recommend sending a housing drawing and operating conditions so our engineering team can recommend the appropriate joint style and material hardness.