Stern tube aft seal

compact, simple, sturdy and effective

Years of experience with the installation and maintenance of existing stern tube sealing systems made Shipyard Kooiman to develop a sealing system herself. Since 2016, Shipyard Kooiman successfully delivers the ‘Kooiman stern tube aft seal.’ In August 2018, Bureau Veritas awarded the ‘Kooiman stern tube aft seal’ with a Type Approval Certificate.

The ‘Kooiman stern tube aft seal’ is compact, simple, sturdy and effective. Our design is suitable for both retro-fit and newbuilding applications. The aft seal is built-up from three main components. A shaft liner which is shrunk around the propeller shaft, a sealing ring which is mounted against the stern tube and an integrated rope guard which is mounted against the propeller hub. The sealing ring houses three Viton oil seals and the rope guard houses two Viton oil seals. The emerged labyrinth of oil seals is filled with grease. To prevent wear of the running surfaces of the oil seals, the shaft liner and sealing ring are provided with a hardened toplayer. All components are manufactured out of seawater resistant materials such as stainless steel 316L and bronze RG12.

All of the above considered, the ‘Kooiman stern tube aft seal’ is the appropriate choice when a compact, reliable and effective aft seal is desired.

The main advantages of our ‘Kooiman stern tube aft seal’ are:

  • Short built-in lengths due to our integrated rope guard.
  • Very good protection of the propeller shaft system against sand, debris, (sea)water, etc.
  • Aft seal is applicable within oil lubricated, grease lubricated and closed – loop water lubricated systems.
  • Our engineers are able to adjust the geometry of the sealing system, this enables installation within existing propeller shaft systems. Of course, this is executed in accordance with the type approval certificate.
  • Short delivery time of spare parts.
  • Bureau Veritas type approval.