Wärtsilä has introduced a new family of face-type seals specifically for water-lubricated stern tubes. These new Deep Sea Seals brand ManeGuard seals are ideally suited to vessels sailing frequently in coastal or other waters with high sand and silt contents. Even under such aggressive conditions, they provide robust seals with high reliability and long service intervals, according to the company. ManeGuard face-type seals are produced for shafts of 70 to 240 mm (3 to 9 inch) diameter, and are either partially split (PS type) or fully split (FS type). They are able to accept high shaft speeds up to 2700 rev/min.
With ManeGuard seals, worn shafts or liners, leaking gland plates and continuous maintenance with their associated costs can be left in the past. The new seal design provides maximum sealing capability for all types of water-lubricated bearings. For stern tubes with closed water systems, ManeGuard seals can be used both inboard and outboard. The seals incorporate interface materials with a high abrasion resistance which, together with a design to minimise galvanic corrosion, dramatically reduce maintenance costs. Thanks to statically-mounted elastomeric body, the seals accept misalignment in all planes and compensate for vibration.
The seals also have various safety features such as automatic compensation for bearing wear, low magnetic signature and inflatable emergency seal. The ManeGuard seals are compact in length and are suited both for retrofit of existing sealing systems or packed glands, and for new construction. In the case of retrofits, the fully-split versions allow the ManeGuard seals to be fitted with the shaft still in place.