7.3.2 Mechanical seal

The mechanical seal has the function of preventing seawater from entering the yacht through the space between the propeller shaft and the hull.
It consists of two rotating rings held in contact by combined forces.
One ring is defined as rotating and rotates with the shaft; the other stationary is fixed to the hull. The structure of the stationary part is made by the use of industrial techno polymers, which guarantee not to run into problems such as ageing or the possibility of drilling or fire.
The seal between the parts is made by means of o-rings.
The cooling of the seal is ensured by the access of water through the flushing duct.

Before starting the engine

Make sure the seal is clean on the outside as well. If foreign bodies are present, it is recommended to wash thoroughly.
Make sure that the flush water valve is open and there are no leaks from the sealing surfaces.

DANGER

Do not approach the shafts when they are rotating.

CAUTION

In order not to compromise the seal, it is essential never to operate it without cooling water.

CAUTION

Bleed the mechanical seals each time the yacht is hauled/launched.

WARNING

RIVA yachts are designed to have a correct transversal trim with full optional equipment, in the presence of propellers and shafts of respect. In case the yacht is not equipped with all the optional extras and with respect shafts and propellers, weights are inserted to compensate and make the trim correct.

Through-hull
O-ring
Stationary support
O-ring
Stationary ring
Rotating ring
O-ring

MAINTENANCE

At least once a week, check that there is no water seepage.
At least once a month carry out a cleaning.
Periodically:

Check the condition of the seals;
Check the compression of the seal and when necessary make a compression;
Check and maintain the cooling circuit of the seals to prevent dirt, algae and foreign bodies from blocking the flow of cooling water, causing the seals to overheat and permanently damage them.

NOTE

For further information on use and maintenance, please refer to the manufacturer’s manual.