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PSS Water-Lubricated Shaft Seal for a Boat's Propeller Shaft

The PSS Type A boat propeller shaft through-hull seal is a maintenance-free mechanical shaft seal that provides a reliable and leak-free solution for sealing boat propeller shafts.
The seal is based on a rotating part attached to a stainless steel shaft and the precision-machined sealing surfaces of a stationary carbon-graphite flange. The sealing surface is lubricated by water. A flexible bellows compensates for longitudinal movement of the shaft, vibration, and minor misalignment, ensuring smooth operation and a long service life without wearing down the propeller shaft.

Technical specifications

  • Operating temperature: -15 °C – +107 °C
  • Maximum pressure: 0.68 bar
  • Maximum spindle speed: 10,000 rpm
  • precision-ground graphite sealing surface
  • AISI 316 stainless steel flange
  • nitrile rubber (NBR-PVC) bellows

The PSS shaft seal is a popular choice for sailboats and motorboats that require a reliable, long-lasting, and virtually maintenance-free shaft seal.

Why choose a water-lubricated PSS seal?

PSS Propeller Shaft Seal for Boats – Maintenance-free and completely leak-proof propeller shaft seal

The PSS shaft seal is a modern solution for sealing a boat’s propeller shaft. It replaces traditional grease tape or Teflon tape seals and eliminates the need for constant tightening, adding grease, and replacing the sealing cord. The result is a dry bilge, more worry-free operation, and a longer service life for the propeller shaft.

Why Choose a PSS Shaft Seal?

✔ Maintenance-free operation
When installed correctly, the PSS shaft seal does not require constant adjustment or tightening. You can install it and focus on enjoying your boating experience without the need for regular maintenance.

✔ A completely dry bilgei
Unlike traditional seal boxes, which intentionally allow a small amount of water to pass through for lubrication, the PSS forms a completely watertight mechanical seal. The bilge remains dry, clean, and odor-free.

✔ Protect the propeller shaft
PSS uses a solid carbon-graphite sealing surface and a rotating stainless steel rotor. This solution prevents shaft wear and scoring that can be caused by traditional sealing cords.

✔ Long service life
The standard PSS shaft seal has a service life of approximately 6 years. The advanced PSS PRO model, featuring a reinforced silicone boot and a locking ring, offers a service life of up to 8–10 years under normal operating conditions.

Key Benefits of the PSS Shaft Seal
✔ Maintenance-free mechanical shaft seal for boats
✔ No leaking bilge water
✔ No need to replace or tighten the sealing cord
✔ Extends the service life of the propeller shaft
✔ Reduces maintenance needs and operating costs
✔ A reliable solution for sailboats and motorboats
✔ Suitable for both professional and recreational boating

The PSS shaft seal is an excellent choice for boaters who value reliability, low maintenance, and a dry bilge. The mechanical seal design provides a safe and long-lasting solution for sealing the propeller shaft and makes boat maintenance significantly easier.

Available in the traditional style PSS gasket and PSS Pro Gasket for demanding conditions.