PSS | Shaft Seal

Overview

Aside from being the number one selling marine mechanical seal worldwide, the PSS Shaft Seal is also recognised as the premier retrofit (aftermarket) seal on the world market.

Boat builders and boatyards recognise the advantages and value of installing the PSS as it eliminates the maintenance, constant adjustment and cost associated with traditional packing type glands. Aside from these benefits, the PSS Shaft Seal helps to eliminate water in the bilge (100% watertight) and wear to the propeller shaft.

The PSS Shaft Seal can be easily retrofitted and is available for shafts ranging from 3/4” to 8” (20mm to 203mm).

The sealing surface is created between a rotating stainless steel rotor (N50 for Type B and Type C models) and a stationary carbon stator. The carbon stator is attached to a convoluted rubber bellow (silicone for Type B and Type C models) and the back of the bellow is attached to the shaft log (stern-tube) of the boat with hose clamps.

During installation, the stainless steel rotor is used to compress the convoluted bellow. The rotor is then secured to the shaft. The compression of the bellow allows the seal faces to remain in constant contact, while compensating for the fore and aft movement of the shaft caused by the propellers thrust pushing on the engine mounts.

The carbon stator is bored slightly larger than the shaft diameter, allowing it to “float” around the shaft and compensate for minor misalignment or vibration problems.

The stainless steel rotor is sealed to the shaft with o-rings. These o-rings rotate with the shaft and rotor and do not experience any wear during operation. This static o-ring seal enables the PSS Shaft Seal to be fitted on shafts that have some wear or pitting, unlike lip seal designs which require a clean area for the lip seal to ride on.

This type of carbon face seal is less sensitive to the interruption of water flow, or operation in silty water, when compared to other sealing options.