8 - PROPULSION SYSTEM273
8.13.4 Mechanical seal
The mechanical seal has the function of preventing sea water from entering
the yacht through the space between the propeller shaft and the hull.
It is made up of two sliding rings kept in contact by combined forces. One
ring is dened as rotating and rotates with the shaft; the other stationary is
bound to the hull.
The seal between the parts is made by means of o-rings.
Cooling of the seal is ensured by the access of water through the ushing
duct.
On your yacht, between the bulkhead and the stationary element, the idrost-
op system can be installed (OPT).
In emergency situations and in case of water inltration from the bulkhead,
the IDROSTOP (if present) allows, once pressure has been applied, through
the special pneumatic connection (max 3 bar), the return to port in complete
safety, keeping the shaft stationary and at reduced speed.
Make sure before starting the engine:
• That the seal is also clean on the outside. If foreign bodies are present,
it is advisable to wash thoroughly.
• That the ush water valve is open and there are no leaks from the seal-
ing surfaces.
• Of the sacricial anode’s state of consumption.
• For medium-long periods of yacht downtime, follow the instructions in
the supplier’s use and maintenance manual.
CAUTION
Install the seal only when the yacht is outside the water.
Flushing connection
for seal cooling
Idrostop attachment
Vent valve
Idrostop flange (opt)
SEA SIDE
Body
gasket
Body
Stationary
ring gasket
Stationary
ring
Rotating
ring
Rotary
ring gasket
Ring nut
Anode
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