－
4
－
3 Maintenance
(1)During normal operation, keep all the sea water piping valves wide open, and also
keep the escape valves of the air piping wide open.
Make sure of the performance of the seal ring periodically. Allowable the amount
of water leakage is shown approximately dropping leakage. That leakage is good
for lubrication and cooling.
(2)Make sure of the performance of the inflatable ring at no shaft rotation before
dry docking.
(3)Avoid supplying over 0.8 MPa air pressure to the inflatable ring.
(4)Install a current collector near the sealing device and carry out maintenance
and inspection thoroughly.
(5)Check and clean the sea water piping as occasion calls.
(6)Bind a hose band tight periodically so that the rubber hose of a sea water piping
does not loosen.
(7)When using fire near the sealing device, use care not to allow fire flames and
sparks to come in direct contact with the sealing device.
4 Replacing procedure of the seal rings at sea
If a large amount of water (over 100
–
200 L/day) leaks continuously, check the
seal ring and replace it if necessary.
(1)Work the inflatable ring according to item 2.
(2)Remove the mating ring.
(3)Finish the sliding surface of the mating ring as flat as possible using emery
paper whenever the mating ring was removed from the casing.
(4)Take the seal ring out of the casing and remove the garter spring.
(5)Cut away the seal ring.
(6)Take out the spare seal ring on the shaft sleeve and set it into the casing
in accordance with item [A]-3-(3).
(7)Fix the mating ring.
(8)After work, close valve
①
, and open valve
②
. Purge air in the casing by opening
plug
③
. And close plug
③
.
[E] Parts replacement intervals
1 Seal ring
The seal life might be considered approximately 2
～
4 years, but a little shorter
in vessels with a deeper draft. In case of the replacement of a seal ring, also replace
the garter spring at the same time.
2 Inflatable ring
This might be used for about 5 years, but it is recommended to replace at the shaft
withdrawal. In addition, if the ring is inflated and damaged due to shaft rotation,
replace the ring immediately.
3
“O” ring
If there are no serious defects or tears in the bonding part, it can be used for
about 5 years. But when disassembling the sealing, replace it, judging from its
condition. It can be easily replaced using instant adhesive.
