－
8
－
[H] Trouble shooting
Term
Method of
inspection
Normal condition
Detected abnormality
Cause of the trouble
Course of action
1
Temp.of the
mating ring
hand inspection
warm to the touch.
less than 50
℃
initial operating temp.
for a new ring may be
higher.
too hot to touch.
smell of burning rubber
noted.
high water pressure due to
excessive water supply.
adjust water pressure. (see term 3)
inflation of inflatable
ring.
release air from the ring.
fishing net caught on
propeller.
remove fishing net.
improperly installed seal
ring.
disassmble mating ring, apply grease on the
shaft sleeve and reset seal ring.
2
Amount of
water
leakage
visual inspection
and measurement
of water leakage
shaft rotating,
seal size
≦
190
:leakage
≦
40L/day
310
≧
seal size
≧
210
:leakage
≦
50L/day
seal size
≧
330
:leakage
≦
80L/day
shaft stationary,
leakage
≦
50L/day
with new seal ring and
reconditioned mating
ring,leakage should be
minimal[approx.10cc/min].
leakage above 100
～
200L/day.
there shoud be no
leakage between seal
ring and shaft sleeve.
something caught between
seal ring and mating ring.
disassemble mating ring, clean mating and
seal rings.
warped seal ring.
pour hot (70
～
80
℃
) water on seal ring.
worn seal ring.
replace seal ring with spare on shaft.
worn mating ring.
(more than 0.5mm depth)
lathe mating ring or turn to the face.
temporary repair : using sandpaper or
grinder, flatten as much as possible.
seal ring hardens due to low
water temperature.
pour hot (70
～
80
℃
) water on seal ring.
something caught between
seal ring and shaft sleeve.
slide seal ring out, clean shaft sleeve and
inside of the seal ring.
rubber adhesive fails
replace seal ring with spare on shaft.
3
Supply water
pressure
check pressure
gauge G-2
hand inspection
visual inspecion
draft pressure
+ 0.01
～
0.03 MPa
mating ring too hot to
touch.
a large amount of water
leakage.
see term 1.
damaged stern tube rubber
bearing
see term 1.
clean inside of box.
4
Inflatable
ring
with shaft
stationary,
inflate ring to
0.3
～
0.6MPa ;
inspect for water
leakage.
air pressure drop is within
10 %/Hr.
no sea water leakage.
inflatable ring cannot
be inflated and water
leakage from air supply
line.
inflatable ring
inflates but leaks sea
water.
ring inflated while shaft
running.
replace as soon as possible.
normally this repair done in dry dock.
however, in an emergency, repair may be done
afloat by pluging stern boss.
insufficient air pressure. increase air pressure.(Max. 1.0 MPa)
supply water line valve left
open.
close the valve
