Frequently
asked questions
|
What's
in the service package?
|
Everything
that is required to change the seals including the precise alignment of
the liner.
|
Can
the job be done afloat?
|
If
the ship can be ballasted by the bow so that the shaft is out of the water
then the seals can be bonded provided there is no other damage.
|
How
long will the job take?
|
Three
days for a standard forward and aft seal on the one shaft, provided that
other dry dock work does not interrupt our work. CPP installations and
split liners will take longer.
|
Can
we replace the sealing rings without pulling the shaft?
|
Yes,
by cutting the sealing rings, then vulcanising the rings with the aid
of a bonding kit, and special two component adhesive.
|
Where
do our service engineers go?
|
Worldwide
|
What
am I likely to need to do at the next docking?
|
Contact
Simplex. We will check our service reports and advise what spares are
required. For instance, a distance ring may be required, or the liner
may need to be machined or a new liner needed.
|
Why
are my seals leaking?
|
All
seals require a small migration of liquid particles under the sealing
ring in order to ensure that the ring is lubricated and cooled. Any water
is accumulated in the Number Two chamber and transfered back to the 20
litre tank where it can be drained off. A leakage of up to 1% of the shaft
diameter is acceptable.
|
I
have 5% oil in the sterntube oil. What should I do?
|
Excessive
leakage may be caused by a large number of factors for example:
-
Excessive
wear seal lips
-
Hard
and/or cracked seals
-
Broken
or damaged seal springs
-
Foreign
bodies under seal lips (fishing line, sand etc)
-
Damage
to seal housing
-
Seal
liners excessively grooved
-
Pitting
corrosion in liners
-
Damaged
gasket or 'O' seal on liner (aft seal)
-
Damaged
'O' seal between liner and clamp ring (forward seal)
-
Excessive
eccentricity on liners
-
Wrong
oil in system (possible corrosive effect on seals)
-
Liners
machined under minimum permissable size
-
Excessive
clearance between sterntube bearings and propeller shaft. (Vibration
can cause pumping effect of oil or water past seals)
-
Damaged
housing gaskets
|
