kemel air seal type kemel ax instruction manual
TRANSCRIPT
KEMEL AIR SEAL
Type KEMEL AX (With Air Relay)
INSTRUCTION MANUAL
Marine Division
http://www.kemel.com
This manual is produced based on a typical lubrication diagram for stern tube system installed with
Type KEMEL AX seals. For correct understanding and operation of the ship’s system, read this booklet
together with seal drawing and the piping diagram available in the finished plan.
Besides this booklet, read Instruction Manual for KEMEL COMPACT SEAL Type KEMEL CX, DX & AX
included in the finished plan.
- 1 -
Contents
1. Outline -------------------------------------- P. 2
1.1 Construction
1.2 Air Control Unit (MU)
1.3 AFT Seal
1.4 S/T L. O. Tank Unit (TU)
1.5 Oil Pressure Unit (OU)
1.6 Drain Collection Unit (CU)
2. Oil Filling & Oil Pressure Test -------------------------------------- P. 5
3. Operation of Air Seal -------------------------------------- P. 5
3.1 Start-up Air Control Unit (MU)
3.2 Operation of Air Seal
4. Daily Maintenance ------------------------------------- P. 8
4.1 Stern Tube System
4.2 Air Control Unit & Drain Collection Unit
5. Trouble Shooting ------------------------------------ P. 10
5.1 Abnormalities of Air Pressures/Air Flow & Actions
5.2 Alarms & Actions
5.3 Other abnormalities & Actions
6. Switch-over to normal Oil Seal System for emergency ---------------- P. 13
7. Operation for Dry-docking, Undocking and Laying-up ---------------- P. 14
7.1 Dry docking & Undocking
7.2 Laying-up
- 2 -
1. OUTLINE
1.1 Construction
Air Seal keeps seawater out by blowing air into sea through an air chamber (Air Chamber) provided at the space
between the #2 & 3 seal rings in AFT seal, and it keeps oil tight by controlling stern tube oil pressure to follow
change of ship’s draft. Segregation of seawater and stern tube oil by Air Chamber minimize the risk of seawater
contamination. Besides, a drain line provided at the bottom of Air Chamber collects and recovers leaking oil and
water in engine room in case of leakage. At the same time, the system automatically optimizes the oil pressure
based on draft pressure detected at Air Chamber and remarkably reduces the pressure load given on AFT seal at
all draft levels. The construction of Type DX seal with a stand-by spare seal ring is employed on AFT seal, which
enables switching-over to the spare at any time by simple valve operation. FWD seal has a same construction as
existing models. The schematic diagram and the components for the system are shown in the sketch below.
Component Function
Air Control Unit
（MU）
Supply air to AFT seal
Regulate supply air pressure
Regulate air flow
Pressurize S/T L. O. Tank
Clean air pipe by fresh water
S/T L. O. Tank Unit
（TU）
Supply oil to Pump
Pressurize stern tube
Oil Pressure Unit
（OU） Circulate stern tube oil - Pump
Drain Collection Unit
（CU）
Recover leaking oil/water
Recover cleaning fresh water
FWD seal L. O.
Circulation Unit Circulate FWD seal L. O.
- 3 -
Air Flow meter
FM1
Air Source
Pressure P1
Blowing Air
Pressure P4
Air Regulator
SUB R2 & P3
Air Regulator
MAIN R1 & P2
MAIN/SUB Change
Lever C1
Air Filters
F1・F2
MU Front View
Air Flow Controller -
MAIN FC1
MU Side View Left
Air Flow Controller
FC2
MU Side View Right
MAIN/SUB Change
Lever C2
TU Air Pressure
P5
Control wheel Air Relay
AR1
Air Filter Drain Drain
Fresh Water Line F/W
TU Line OUT2
Air Blow Line OUT1
Air Source IN
MU View Bottom Panel
Test Line OUT3
DifferentialPressure Gauge
DP
1.2 AIR CONTROL UNIT (MU) Air Control Unit (MU) regulates supplied compressed air at the pressure*) set by Air Regulator (R1) and at the
flow rate*) set by Air Flow Controller (FC1) after passing Air Filters (F1 & F2). Then the regulated air lead to Air Chamber in AFT seal is blown into sea, called Air Blow Line which has a branch line to Air Relay (AR1) to give the pressure of air blowing as an input signal. Another branch line taken after Air Filters is lead to S/T L. O. Tank Unit (TU) through AR1 to pressurize it, called TU Line. AR1 regulates the pressure in TU Line at the level of the signal pressure from air blowing. AR1 has a hand wheel for fine adjustment of the regulating pressure. TU Line has change lever C2 to bypass AR1, through SUB Line, which gives TU a direct pressure from Air Blow Line. MU has a spare Air Regulator (R2) and a spare Air Flow Controller (FC2) on SUB LINE for switching over from R1 & FC1 on MAIN LINE by C1 Lever. Also MU has Fresh Water Line for periodical cleaning of air purging pipe and has an Alarm Switch for Air Pressure Low. Air Regulators R1 and R2 have pressure gauges P2 and P3 for stetting air pressure. Dirtiness of Air Filters (F1 & F2) is examined by visual and Differential Pressure Gauge (DP). The gauge P1 indicates air source pressure and the gauge P4 indicates Air Blow Line pressure. *) Set values of Air Regulators and Air Flow Controllers are shown in “Finished Plan – Piping Diagram Fig. 1”.
- 4 -
Oil Level High/Low
Alarm switches
TU Top View
Oil level
gauge
Drain Valve
（N. C.）
TU Front View
TU Line
connection
Air Vent
（N. C.）
Safety Relief
Valve
1.3 AFT Seal
Air supplied from MU to AFT Seal blows out underwater
through Air Chamber, with the pressure set by Air
Regulator. The effects of air blow are explained below;
1) When the pressure in Air Chamber slightly exceeds
the tension forces from the #1 & #2 seal rings +
seawater pressure from the draft, the air lifts up the
#1 & #2 seal lips and starts blowing into sea through
the gap, formed by the lift, with the constant rate set by
Air Flow Controller.
2) The gap by constant air blow makes Air Chamber
being kept opened in-water all the time.
3) By this, Air Chamber pressure (= Air Blow Line
pressure P4) is equalized to the level of tension forces from the #1 & #2 seal rings + seawater pressure
from the draft or slightly above.
Because of the opening underwater, Air Chamber pressure does not go higher up to the pressure set by Air
Regulator, and also continual air blowing prevents seawater penetration into Air Chamber. Air Flow Controller
keeps constant flow and maintains the gaps under all draft level of the ship. Therefore the pressure in Air
Chamber follows water pressure from draft change with no time-delay. In addition, air from MU partly returning to
Drain Collection Unit (CU) with slight ventilation in E/R generates low speed air flow to remove leaking oil or
water from Air Chamber, through a drain hole provided at the bottom lead into CU.
The #3 & #3S seal rings can be switched over by valve operation in E/R. (Valve “C” & “D” shown in the piping
diagram P. 6.) Open these valves for the #3 in use and close them for the #3S in use.
1.4 S/T L. O. Tank Unit (TU)
TU is an air-tight oil tank having 100 - 200L capacity and is installed to give oil head pressure in stern tube with 2
- 2.5M of the oil height above shaft centerline. In addition, TU is connected with an air pipe via AR1 equalizing the
line pressure at Air Chamber Pressure. By the arrangement, stern tube is pressurized at the level of oil head
pressure + Air Chamber Pressure which is loaded onto the #3 seal ring, supported at the same time by Air
Chamber Pressure from seawater side while air blows out as described in Article 1.3. Because of Air Chamber
Pressure at the front face and the back of the #3 seal ring, it counteracts each other cancelling the force. As a
result, the actual load remains on the #3 seal ring is oil head pressure of TU constant at all draft. Same effect is
available on the #3S seal ring when it is in use. TU is provided with Safety Relief Valve to avoid excessive
pressure, and Alarm Switches for Oil Level High & Low. TU is also connected with Oil Pressure Unit (Oil
pumps) to circulate stern tube oil.
- 5 -
Level
Gauge
Air Flow Controller FC
CU
High Level
Alarm Switch
Joint for AFT seal
drain pipe
Drain Valve
(N. C.)
Air Vent
1.5 Oil Pressure Unit (OU – Oil Pump)
OU circulates lubrication oil via “OU ➔ Stern Tube ➔ TU ➔ OU”. Stern tube oil pressure is measured at the
return line from stern tube to TU. The correct pressure is calculated by adding (or deduction on some cases) oil
head pressure from the gauge height to the reading value. (See calculation example in P.7.) Periodically examine
oil suction & discharge pressures on the pumps, and clean strainers for maintenance whenever is necessary.
1.6 Drain Collection Unit (CU)
CU is an air-tight tank with 10L capacity and is located
below the shaft level. CU is connected to a drain pipe from
Air Chamber in AFT seal. Flow Controller (FC) fitted on
CU gives air-flow at a low speed (about 5 L/min.) from Air
Chamber towards CU to remove leaking seawater and oil
into CU through the pipe. Drain recovered can be
discharged by the air pressure in CU, through Drain Valve.
(Discharge drain while M/E is stopped.) CU is fitted with
Level Gauge and High Level Alarm Switch
2. Oil Filling and Oil Pressure Test
Procedures for oil filling to stern tube and oil pressure test for Air Seal is described in P. 6. Confirm actual valve
operation for oil filling, circulation, draining & etc. in ship’s piping diagram available in finished plan.
3. Operation of Air Seal
3.1 Start-up Air Control Unit (MU)
When air supply to Air Seal become available, start-up MU after filling oil in stern tube by the procedures below,
1) Put valve positions in MU for blowing air as per Finished Plan – Piping Diagram Fig. 1.
2) Close Air Vent on TU and Drain Valve on CU.
3) Put valve positions for oil circulation via “TU ➔ OU ➔ Stern Tube ➔ TU”, then start-up OU.
4) Open air source valve for MU.
5) Adjust settings for Air Regulator R1 and Air Flow Controller FC1 if necessary.
6) Confirm air blowing at AFT seal in dry-dock, or at sea surface in stern area after launching.
7) Record all data by using the form shown in P. 7, and examine the system is working right.
8) Adjust stern tube oil pressure Ps/t by operating bypass valve on OU and AR1 on MU if necessary.
9) Put Change Lever C1 on SUB and examine all pressures. (FM1 does not work with SUB in use.)
10) Put Change Lever C2 on SUB and examine all pressures.
11) Put Change Levers C1 & C2 on MAIN for normal operation.
In case of launching a new ship with no air blowing, examine CU periodically for possible water penetration after floatation.
3.2 Operation of Air Seal
Air Seal System is in operation when blowing air into sea is started. The system automatically controls stern tube oil
pressure at the optimum level responding to changes of ship’s draft. Keep blowing air and operating OU all the time
while the ship at sea as well as at berth or anchor. OU may be stopped for maintenance etc. while M/E is stopped. In
case air source is shut off, stern tube oil pressure stays at the level of oil head pressure from TU. Closely watch
seawater penetration in CU in such an event, and recover or establish air supply as soon as possible. Maintenance of
stern tube system, MU and CU is done as per the article 4 in P. 8.
- 6 -
TYP
ICA
L D
IAG
RA
M -
Co
nfi
rm v
alve
no
.s &
de
tail
s in
Fin
ish
ed
Pla
nTe
st
Ord
e
Seal
Rin
gP
roce
du
re
1#3
S
1)
Fill
ster
n t
ube
and
TU
wit
h o
il. -
See
left
"P
roce
du
re O
il Fi
llin
g".
2)
Kee
p v
alve
s "C
" &
"D
" cl
ose
d.
3)
Ap
ply
oil
pre
ssur
e in
ste
rn t
ube.
4)
Rem
ove
bo
tto
m p
lug
bet
wee
n #
3 &
3S
seal
rin
gs o
n A
FT s
eal c
asin
g.
5)
Cle
an
up
sea
l cas
ing/
liner
/oil
ho
les
to r
emo
ve o
il w
et.
6)
Lea
ve t
he
plu
g o
pen
ed f
or
mo
re t
han
3 h
ou
rs.
7)
Co
nfi
rm n
o o
il le
aki
ng
thro
ugh
the
bo
tto
m h
ole
.
8)
Co
nfi
rm n
o o
il le
aki
ng
at o
ther
are
a, i
. e.
shee
t p
acki
ng,
"O
" ri
ng
& e
tc.
2#4
1)
Sam
e pr
oce
du
res
as 1
) &
2)
for
test
ing
#3S
abo
ve.
2)
Rem
ove
bo
tto
m p
lug
bet
wee
n #
4 &
5 s
eal r
ings
on
FW
D s
eal c
asin
g.
3)
Cle
an
up
sea
l cas
ing/
liner
/oil
ho
les
to r
emo
ve o
il w
et.
4)
Lea
ve t
he
plu
g o
pen
ed f
or
mo
re t
han
3 h
ou
rs.
5)
Co
nfi
rm n
o o
il le
aki
ng
thro
ugh
the
bo
tto
m h
ole
.
6)
Co
nfi
rm n
o o
il le
aki
ng
at o
ther
are
a, i
. e.
shee
t p
acki
ng,
"O
" ri
ng
& e
tc.
3#3
1)
Plu
g al
l oil
ho
les/
dra
in h
ole
s b
etw
een
#3
& 3
S o
n A
FT s
eal c
asin
g.
2)
Op
en v
alve
s "C
" &
"D
", t
o a
pp
ly p
ress
ure
in #
3/3
S ch
amb
er.
3)
Clo
se v
alve
"H
" fo
r ab
ou
t 3
0 s
ec. t
o d
irec
t o
il fl
ow
s in
to #
3/3
S ch
amb
er.
4)
Kee
p v
alve
"H
" o
pen
aga
in f
or
the
test
.
5)
Rem
ove
bo
tto
m p
lug
bet
wee
n #
2 &
3 o
n A
FT s
eal c
asin
g.
6)
Cle
an
up
sea
l cas
ing/
liner
/oil
ho
les
to r
emo
ve o
il w
et.
7)
Lea
ve t
he
plu
g o
pen
ed f
or
mo
re t
han
3 h
ou
rs.
8)
Co
nfi
rm n
o o
il le
aki
ng
thro
ugh
the
bo
tto
m h
ole
.
4#2
1)
Lea
ve b
ott
om
plu
g b
etw
een
#2
& 3
op
ened
.
2)
Plu
g b
ott
om
ho
le b
etw
een
#1
& 2
.
3)
Rem
ove
tw
o p
lugs
on
to
p b
etw
een
#1
& 2
, fo
r fi
llin
g an
d a
ir v
enti
ng.
4)
Fill
#1/2
ch
amb
er w
ith
"Fre
sh W
ater
" th
rou
gh t
he t
op
ho
le.
5)
Cle
an
up
sea
l cas
ing/
liner
/fill
ing
ho
les
to r
emo
ve w
et.
6)
Co
nfi
rm n
o w
ater
lea
kin
g th
rou
gh t
he b
ott
om
ho
le b
etw
een
#2
& 3
.
5#1
1)
Sam
e pr
oce
du
res
1)
- 5
) fo
r te
stin
g #2
sea
l rin
g ab
ove
.
2)
Co
nfi
rm n
o w
ater
lea
kin
g o
ut.
3)
Dra
in o
ut
Fres
h W
ater
aft
er t
he t
est.
4)
Co
nfi
rm a
ll h
ole
s fo
r fi
llin
g, d
rain
ing
& a
ir v
enti
ng
on
AFT
sea
l plu
gged
.
6#5
1)
Plu
g al
l ho
les
bet
wee
n #
4 &
5 o
n F
WD
sea
l cas
ing.
2)
Fill
#4/5
ch
amb
er w
ith
oil.
3)
Cle
an
up
sea
l cas
ing/
liner
to
rem
ove
oil
wet
.
4)
Co
nfi
rm n
o o
il le
aki
ng
ou
t.
5)
Co
nfi
rm a
ll o
il h
ole
s o
n F
WD
sea
l plu
gged
aft
er t
he t
est.
LEA
K T
EST
PR
OC
EDU
RE
in d
ry-d
ock
(A
IR S
eal
Typ
e A
X)
RE
MA
RK
S
1. C
arry
out
leak
tes
t af
ter
com
ple
tion o
f fl
ush
ing
pip
es.
2. T
ake
wea
r-dow
n r
eadin
gs b
efore
and a
fter
over
hau
ling
AF
T s
eal, f
or
repai
r sh
ip.
3. P
rote
ct s
eals
fro
m s
and b
last
ing,
pai
nting,
wel
din
g, c
hem
ical
s, e
xces
sive
hea
t &
etc
.
4. U
se s
tain
less
ste
el f
ittin
g b
olts
(SU
S 3
16 o
r eq
uiv
alen
t) f
or
AF
T s
eal
inst
alla
tio
n.
5. S
ecure
all
the
fitt
ing
bolts
and p
lugs
for
AF
T s
eal
by u
sing
stai
nle
ss s
teel
wir
e.
6. P
ut al
l val
ves
(an
d r
egula
tor
sett
ing)
bac
k t
o "
Norm
al O
per
atin
g C
onditio
n"
afte
r th
e te
st.
7.C
hec
kP
2 p
ress
ure
in
dic
atio
n fo
r R
egu
lato
r o
n t
he
gree
n m
ark
.8.O
il le
vel
may
sudden
ly r
educe
when
air
-lock
ing
dis
solv
ed.
Fill
oil
in s
uch
an e
ven
t.
Pro
ced
ure
Oil
Filli
ng
1)
Fill
Sum
p t
ank,
-O
pen
Val
ve "
I".
2) C
lose
air
so
urce
val
ve f
or
MU
, and
ope
n a
ir v
ent
on
TU.
3)
Clo
se v
alve
s "C
"&
"D
", a
nd
op
en v
alve
"G
".4
) K
eep
val
ves
"A"
& "
H"
op
en,
and
clo
se v
alve
"B
".5)
Fill
ste
rn t
ube
and
TUw
ith
oil
by o
pera
ting
OU
.6
) St
op
OU
afte
r T
Ufi
lled
up
wit
h h
alf
leve
l.7
) C
lose
air
ven
t o
n T
U.
8)
Car
ry o
ut
Test
Ord
er
"1"
& "
2",
eit
her
by
usi
ng;
a) "
X"-
line,
or
b) A
ir p
ress
ure
9)
Fill
oil
in #
3/3
S b
y Te
st O
rde
r "3
" af
ter
"1"
& "
2".
10
) Fi
ll o
il #4
/5 b
y Te
st O
rde
r "6
" af
ter
"3",
"4
" &
"5
".
Leak
te
st v
ia "
X"-
line
1)
Clo
se v
alve
s "A
"&
"B
".
2) K
eep
val
ve "
G"
ope
ned
. Ke
ep v
alve
s "C
"&
"D
"cl
ose
d.
3)
Op
erat
e O
U4
) C
ircu
late
oil
via
Sum
p T
k➟
S/T➟
"X"-
line➟
Sum
p T
k fo
r te
st.
Leak
te
st b
y ap
ply
ing
air
pre
sssu
re in
MU
1)
Clo
se v
alve
"G"
on
oil
line.
2) O
pen
val
ves
"A",
"B
"&
"H
"o
n o
il lin
e.3
) K
eep
val
ves
"C"
& "
D"
clo
sed
.4
) C
lose
air
ven
t o
n T
U.
5) O
pera
te O
U,
and
circ
ulat
e o
il vi
a TU
➟S/
T➟
TUfo
r tes
t.6
) Se
t va
lve
po
siti
on
s in
MU
are
fo
r A
ir B
low
. 7
) R
edu
ce R
egu
lato
r se
ttin
g (0
.2 -
0.4
MP
a) o
n "
MU
"to
0.1
MP
a.8
) 8
) C
lose
val
ve "
E", o
r V
4va
lve
in M
U.
9) C
heck
Ps/
t sh
ow
s ab
out
0.1
MPa
and
pro
ceed
fo
r the
tes
t.
Ap
ply
oil
pre
ssur
e in
ste
rn t
ube
eith
er b
y X
-lin
e o
r b
y ai
r p
ress
ure,
an
d c
arry
o
ut t
he t
est
in a
cco
rdan
ce w
ith
the
pro
ced
ure
sho
wn
in t
he t
able
.
1. V
alve
po
siti
on
ssh
ow
n a
bo
ve a
re f
or
"No
rmal
Op
erat
ing
Co
nd
itio
n"
of A
ir S
eal S
yste
m.
2. "
X"-l
ine
is f
or
oil
circ
ulat
ion
via
the
grav
ity
line,
no
t in
use
dur
ing
ope
rati
on
of A
ir S
eal S
yste
m.
- 7 -
P1
P2
P3
P4
P5
DP
F1
F2
FM
1C
1C
2P
dFC
Leve
l ga
uge
Ps/
tSU
C.
DIS
C.
Air
sourc
epr
ess
.(M
Pa)
Reg.
air
press
.M
ain
(MPa)
Reg.
air
press
.Sub
(MPa)
Blo
wai
rpr
ess
.(M
Pa)
TU
lin
eai
rpr
ess
.(M
Pa)
Diff.
air
press
.(M
Pa)
Air f
ilter
Oil
mis
tfilter
Air f
low
mete
r(L
/m
in.)
Chan
gele
ver
Chan
gele
ver
Air
press
.(M
Pa)
Air f
low
contr
ol
Liq
uid
in
tank
Leve
lfr
om
Tk
bott
om
(cm
)
Leve
l fr
om
Tk
bott
om
(cm
)
S/T o
ilpr
ess
.(M
Pa)
Oil
press
.(M
Pa)
Oil
press
.(M
Pa)
110.4
0.7
0.3
00.1
10.1
0.0
1C
lean
Cle
an40
Mai
nM
ain
0.0
9flow
em
pty
043
0.1
10.1
10.1
7#1
70
32
Sam
ple
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
Cle
an/D
irty
Cle
an/D
irty
Mai
n/S
ub
Mai
n/S
ub
flow
/no
em
pty/
oil/
sw#1/#2
5. P
ut
air
vent
pipe
of FC
in a
wat
er
cup
to c
heck
air
flow
ing
at D
rain
Colle
ction U
nit.
Sym
bol
Sym
bol
Val
ue
DP
h
FM
1H
p
P1
P2
Sym
bol
MPa
P3
Ps/
t
*** A
djust
sett
ings
show
n in F
inis
hie
d Pla
n -
Pip
ing
Dia
gram
Fig
. 1.
Pd
ΔP
Hp
ΔP +
Hp
Diffe
rential
pre
ssure
com
pensa
ted
0.0
3-0.0
5M
Pa r
ange
0.0
335
Diffe
rential
Pre
ssure
Ps/t
- P
d-
0.0
2
Heig
ht
of
shaf
t cente
rlin
e a
bove
keel (m
)H
ead
pre
ssure
Ps/t
gauge
*by
cal
cula
tion
0.0
135
0.2
5 -
0.3
5M
Pa o
n M
AIN
, 0M
Pa
on S
UB
***
Check
poin
t 2.
Rem
ark
Exam
ple
0M
Pa
on M
AIN
, 0
.25
- 0
.35
MP
a o
n S
UB
***
Ste
rn t
ube
oil
press
ure
Var
iabl
e b
y dr
aft. P
d sh
ow
snear
ly d
raft
pre
ssure
.0.1
1
Pre
ss. in
Dra
in C
olle
ction U
nit
0.0
9
40 o
r 50L/m
in.
*
**
Head
pre
ssure
(M
Pa)
Ps/t
gauge
*G
auge
heig
ht
x 0.0
09
0.0
135
More
than
0.4
MP
a* F
ill (-) m
inus
valu
e in c
ase t
he g
auge
locat
ed
belo
w s
haf
t le
vel.
Sta
nda
rd s
ett
ing
Check
poin
t 1.
Rem
ark
Exam
ple
Gre
en r
ange
(le
ss t
han
0.1
MPa)
Gau
ge h
eig
ht
above
shaf
t C
/L (
m)
Ps/t
gauge
1.5
2. P
4, P
5, P
d &
Ps/t
press
ure
s au
tom
atic
ally
follo
w c
han
ge o
f w
ater
press
ure
fro
m t
he d
raft
.3. C
lean
filt
ers
in c
ase o
f pr
ess
ure
ris
e in D
P g
auge
.4. C
lean
pum
p st
rain
ers
in c
ase o
f su
ction p
ress
ure
dro
p on O
il P
ressure
Unit
.
6. U
se t
his
form
in o
pera
ting
the s
yste
m w
hile
the v
ess
el at
sea,
at
bert
h o
r in
sea
tria
ls.
Init
ial
Sett
ing
Calc
ula
tion o
f dif
fere
nti
al
pre
ssure
at
shaft
cente
rlin
e
M/E
rpm
S/T B
'rg
Tem
p.(D
eg.
. C
)Rem
ark
Leve
l ga
uge
in U
se
1. R
ecord
ing
inte
rval
s; O
nce a
day
REC
OR
D F
OR
M -
KEM
EL A
ir S
eal S
yste
myy
m
m
M/V
Dat
eAFT
Dra
ft(M
)
Air
Contr
ol
Unit
Dra
in C
ollecti
on U
nit
(10L)
S/T
L.O
. T
ank U
nit
Oil P
ressure
Unit
Oil
leve
lFW
Dse
al T
k(L
)
- 8 -
Unit Devices SymbolStandard
settingMaintenance
Air Source － 0.4MPa Min. Fully open air source valve and keep the pressure above 0.4MPa all the time.
Differential
Pressure
Gauge
DP
Air FilterF1
F2
Air
Regulator
R1/P2&
R2/P3
Set Value
See Note *)
Allowance
±0.05MPa
Air Flow
Controller
FC1&
FC2
Air Flow
MeterFM1
Air Relay AR1
"Ps/t -Pd" value
in the range
0.03 -0.05
MPa
Change
LeverC1 on MAIN
Change
LeverC2 on MAIN
Air Flow
ControllerFC Slight Open
Level
Gauge－ －
Note *) Adjust settings shown in Finished Plan - Piping Diagram Fig. 1.
CU
Less than
0.1MPa
in green
zone
Set Value
See Note *)
Allowance
±5L/min.
MU
In red zone ➟ Clean or renew filters.
① Open V10 and close V1 & V2 in MU.
② Open V3 to release air in the line.
③ Remove filter covers. (Secure O-ring fitted)
④ Remove filters.
⑤ Clean & re-set filters, or renew filters.
⑥ Close V3. Open V1 & V2, then close V10.
Note: Initial setting is made for R1 & R2 at the time of delivery.
Flow setting（the value shown in Finished Plan-
Piping Diagram Fig.1.）
① Pull-up the knob to unlock.
② Check air flow rate at FM1.
③ Turn the knob for flow setting.
④ Push-down the knob to lock.
Note: Initial setting is made for FC1 & FC2 at
the time of delivery.
① Check ventilation through the vent, with low air-speed.
② Turn the knob to adjust flow speed after the lock nut loose, if necessary.
③ Tighten the lock nut after setting air flow.
Note: Initial setting is made for FC at the time of delivery.
Put air-vent pipe in a water cup to check ventilation bubbles.
① Remove drain in case of high level alarm activated.
② Slight-open drain valve for discharge by air pressure in CU.
③ Discharge while M/E stopped.（Do not open the valve when M/E in operation.）
① Main; AR1 controls air pressure in TU line by using Air Blow Line pressure as a signal.② Sub; bypass AR1 and pressurize TU line by direct pressure of Air Blow Line.
③ SUB is only for temporally use.④ Recover MAIN to replace SUB as soon as possible.
Adjust Ps/t （See P.7 Calculation of differential pressure ）
① Loosen lock-nut for control wheel② Turn clockwise to increase, conuter clockwise to decrease③ Adjust stern tube pressure④ Tighten the lock-nut
Gauge P2
Counter
clockwise
（－）
Clockwise
（＋）
Mating
mark
Control Knob: Pull Down-Unlock, Up-Lock
Counter
clockwise
（－）
Clockwise
（＋）
Control Knob: Pull Up-Unlock, Down-Lock
Counter clockwise（－）
Clockwise（＋） Control Wheel
Pressure setting (Set value is shown in Finish
Plan – Piping Diagram Fig.1）
① Pull-down the knob to unlock.② Turn the knob for pressure setting.③ Push-up the knob to lock.
Check positions of Green Markers in P2 & P3 gauges for indication of the set value.
① On MAIN: Air blows into sea via R1➟P2➟FC1➟FM1.
② On SUB: Air blows into sea via R2➟P3➟FC2, bypassing FM1.
③ SUB is only for temporally use. (FM1 does not work.）
④ Recover MAIN to replace SUB as soon as possible.
① Remove drain in case of high level alarm activated.
② Slight-open drain valve for discharge by air pressure in CU.
③ Discharge while M/E stopped.（Do not open the valve when M/E in operation.）
4. Daily Maintenance
4.1 Stern Tube System
Record and monitor operation of Air Seal as per the form in P. 7. Also monitor stern tube system as per
Operating Guideline shown in KEMEL COMPACT Seal Type CX, DX & AX INSTRUCTION MANUAL.
In case of questions on the data or operating condition, send the record to Technical Service Dept. at
“techservice＠kemel.com” for examination and comments.
4.2 Air Control Unit & Drain Collection Unit
Table below shows maintenance of MU and on CU. Also refer to photo manual in P. 9.
- 9 -
- 10 -
Un
itG
auge
Abnorm
alit
yP
ossib
le C
ause
Action
P1
Low
, or
“Zero
” pre
ssure
.
（M
inim
um
0.4
MP
a r
equired.）
Air s
ourc
e v
alv
e c
losed.
Air s
ourc
e p
ressure
low
.
P1 g
auge m
alfunction.
Open a
ir s
ourc
e v
alv
e.
Keep the p
ressure
above 0
.4M
Pa.
Re
pla
ce
P1 g
auge.
P2
Low
, or
“Zero
” pre
ssure
.
Ch
an
ge L
eve
r C
1 is o
n S
UB
.
Air R
egula
tor
R1
settin
g c
hanged.
P2 g
auge m
alfunction.
Air r
egula
tor
R1 m
alfunction.
Put
C1
on
MA
IN,
if it w
ork
s.
Re
-ad
just
R1 s
ettin
g.
Re
pla
ce
P2 g
auge
Put
C1
on S
ub
. R
epla
ce R
1.
P3
Low
, or
“Zero
” pre
ssure
.
Ch
an
ge L
eve
r C
1 is o
n M
AIN
.
Air R
egula
tor
R2
settin
g c
hanged.
P3 g
auge m
alfunction.
Air r
egula
tor
R2 m
alfunction.
No
action
re
quire
d.
Keep C
1 o
n M
AIN
.
Re
-ad
just
R2 s
ettin
g.
Re
pla
ce
P3 g
augeR
epla
ce R
2.
Ris
es u
p to
R1 (
or
R2)
se
t pre
ssu
re.
Valv
es o
n A
ir B
low
Lin
e a
re c
losed.
3-w
ay v
alv
e o
n A
ir B
low
Lin
e in d
irection F
/W c
leanin
g.
Open the v
alv
es.
Put 3-w
ay v
alv
e in d
irection o
f air
blo
win
g.
Gets
hig
her
pre
ssure
in the s
am
e d
raft level
befo
re.
Blo
ckade p
roceedin
g in A
ir B
low
Lin
e.
Cle
an
pip
eby
usin
gfr
esh
wa
ter
line
inM
U,
wh
ileM
/E
sto
pped.
Low
, or
“Zero
” pre
ssure
.A
ir leakage fro
m a
ir p
ipes
Ch
eck p
ipe
s b
y s
pra
yin
g s
oa
p w
ate
r, a
nd
re
pa
ir.
The p
ressure
does n
ot fo
llow
change o
f dra
ft.
P4 g
auge m
alfunction
Re
pla
ce
P4 g
auge.
Co
nsid
era
bly
lo
we
r th
an
P4 p
ressure
.
Pre
ssure
gauge m
alfunction.
Wro
ng
se
ttin
g A
R1
.
Air leakage o
n T
U lin
e
Ma
lfu
nctio
n A
R1.
Re
pla
ce
pre
ssu
re g
au
ges.
Re
-ad
just
AR
1.
Ch
eck p
ipe
s b
y s
pra
yin
g s
oa
p w
ate
r, a
nd
re
pa
ir.
Put
C2 o
n S
ub
. R
ep
lace
AR
1.
Co
nsid
era
bly
hig
he
r th
an P
4 p
ressure
.
Pre
ssure
gauge m
alfunction
Wro
ng
se
ttin
g A
R1
.
Ma
lfu
nctio
n A
R1.
Re
pla
ce
pre
ssu
re g
au
ges.
Re
-ad
just
AR
1.
Put
C2 o
n S
ub
. R
ep
lace
AR
1.
DP
Indic
ato
r needle
in “
Red Z
one”.
Dirty
filt
ers
F1 &
F2
.C
lea
n o
r re
pla
ce f
ilte
rs.
FM
1O
ut of settin
g r
ange.
Air F
low
Contr
olle
r F
C1 s
ettin
g c
hanged.
Air F
low
Contr
olle
r F
C1m
alfunction.
Air F
low
Mete
r F
M1
malfunction.
Re
-ad
just
FC
1 s
ettin
g.
Put
C1on S
UB
. R
ep
lace
FC
1.
Put
C1on S
UB
. R
ep
lace
FM
1.
Pre
ssure
low
.D
rain
va
lve o
r A
ir F
low
Co
ntr
olle
r F
C fully
opened.
Blo
ckage o
r air leakage a
t dra
in p
ipe lead to C
U.
Clo
se
dra
in v
alv
e o
r re
-ad
just
FC
slig
ht open.
Cle
an
pip
e b
y fre
sh
wate
r lin
e in
MU
, re
pair p
ipe.
Pre
ssure
does n
ot fo
llow
change o
f dra
ft.
Pd
gauge m
alfunction
Re
pla
ce
Pd
gauge
Le
ve
l
Gau
ge
Fill
ed
with
se
aw
ate
r.
Fill
ed
with
oil.
Seaw
ate
r le
akage thro
ugh the #
1 &
2 s
eal ri
ngs.
Oil
leakage thro
ugh the #
3 s
eal ring.
Rem
ove w
ate
r. R
ecord
daily
am
ount and r
eport
.
Rem
ove o
il. R
ecord
daily
am
ount and r
eport
.
Ps/t
sta
ys a
t head p
ressure
of
TU
, or
does n
ot
rise
.
Air v
ent valv
e o
n T
U is o
pened.
Air leakage a
t th
e p
ipe lead to T
U o
r T
U its
elf.
Ps/t
gauge m
alfunction.
Clo
se
air v
en
t valv
e.
Ch
eck p
ipe
s b
y s
pra
yin
g s
oa
p w
ate
r, a
nd
re
pa
ir.
Re
pla
ce
Ps/t
gauge
“P
s/t
– P
d” v
alu
e is g
reate
r th
an 0
.05 M
Pa, w
ith
com
pensation o
f P
s/t
gauge h
eig
ht.
Valv
e “
A”
on r
etu
rn lin
e to T
U is n
ot fu
lly o
pened.
Bypass v
alv
e o
n O
U is fully
clo
sed.
Tu
Lin
e p
ressure
too h
igh.
Fu
lly o
pe
n v
alv
e “
A”,
sh
ow
n in P
. 2
dia
gra
m.
Re
-ad
just th
e b
yp
ass v
alv
e.
Adju
st
TU
lin
e p
ressure
by A
R1
hand w
heel.
TU ・
OU
Ps/t
5. T
rou
ble
Sh
oo
tin
g
5.1
Ab
no
rmaliti
es o
f A
ir P
ressu
res/A
ir F
low
& A
cti
on
s
MU
P4
P5
CU
Pd
- 11 -
AL
AR
MU
nit
Ch
ec
k P
oin
tA
bn
orm
al
Co
nd
itio
nP
ossib
le C
au
se
Ac
tio
nR
ep
ort
to
KE
ME
L
DP
Gauge
Th
e in
dic
ato
r in
Red
Zo
ne
, e
xce
ed
ing
0.1
MP
a.
Dirty
filt
ers
.C
lea
n o
r re
pla
ce f
ilte
r ele
me
nts
.
P2
Gauge
P2 indic
ate
s b
elo
w the m
inim
um
set pre
ssure
.
(se
e F
inis
he
d P
lan
– P
ipin
g D
iagra
m F
ig.
1)
R1
se
ttin
g c
ha
ng
ed
.
Ma
lfu
nctio
n R
1.
Ma
lfu
nctio
n P
2.
Re
-ad
just
R1 s
ettin
g.
Put
C1
on S
UB
.
Re
pla
ce
R1
.
Re
pla
ce
P2
.
FM
1 F
low
Me
ter
Flo
w r
ate
is b
elo
w t
he
min
imu
m v
alu
e.
(se
e F
inis
he
d P
lan
– P
ipin
g D
iagra
m F
ig.
1)
FM
1 s
ett
ing c
ha
ng
ed
Ma
lfu
nctio
n F
M1.
Re
-ad
just
FC
1 s
ettin
g.
Put
C1
on S
UB
.
Re
pla
ce
FC
1.
Va
lve
po
sitio
ns
Wro
ng
po
sitio
n. (s
ee F
inis
hed P
lan –
Pip
ing D
iagra
m F
ig. 1)
－C
orr
ect
valv
e p
ositio
ns.
TU
Safe
ty r
elie
f valv
e
Air p
ipe
jo
ints
Air v
en
t
Th
e r
elie
f va
lve
activa
tes a
t lo
we
r pre
ssu
re.
Air le
aka
ge
. (C
he
ck b
y s
pra
yin
g liq
uid
soa
p.)
Air v
en
t va
lve
op
en
ed
.
Ma
lfu
nctio
n v
alv
e.
Loose join
ts e
tc.
－
Re
pa
ir/R
ep
lace
th
e r
elie
f va
lve
.
Re
pa
ir lea
kin
g join
ts/p
ipe
s.
Clo
se
the
va
lve
.
CU
Flo
w C
ontr
olle
r F
C
Air p
ipe
jo
ints
Dra
in V
alv
e
Exc
essiv
e a
ir f
low
at
FC
.
Air le
aka
ge
. (C
he
ck b
y s
pra
yin
g liq
uid
soa
p.)
Dra
in v
alv
e le
ft o
pe
ne
d.
Settin
g c
hanged.
Loose join
ts e
tc.
－
Re
-ad
just
FC
with 2
-3 a
ir b
ubble
s/s
ec.
Re
pa
ir lea
kin
g join
ts/p
ipe
s.
Clo
se
dra
in v
alv
e.
Loss o
f air
sourc
e p
ressure
.－
Ta
ke
actio
ns in
P.
13
. R
eco
very
of
air
OU
Pre
ssure
gauge
Str
ain
er
Oil
colo
r
Ne
ga
tive p
ressu
re a
t p
um
p s
uction
, ca
use
s a
ir s
uckin
g.
Dirty
str
ain
er.
Air b
ub
ble
s（
Incre
ase
d o
il vo
lum
e b
y a
ir in
clu
sio
n.）
Dirty
str
ain
er
Part
icle
s in S
/T o
i
Air in
clu
sio
n
Cle
an
str
ain
ers
.
TU
Level gauge
Level in
cre
ase in s
hallo
w d
raft a
nd d
ecre
ase in d
eep d
raft
Air-p
ocke
t in
S/T
.D
isso
lve
air-p
ocke
t.Y
es
S/T
Ste
rn tube d
rain
Sig
n o
f seaw
ate
r penetr
ation.
CU
Level gauge
Fill
ed
with
se
aw
ate
r im
me
dia
tely
aft
er
dra
inin
g.
FW
D
se
al
Level gauge
De
cre
ase
oil
leve
lin
FW
Dse
al
tank,
and
incre
ase
the
leve
l in
TU
with s
am
e a
mount. (
Pum
pin
g e
ffect.)
Pre
ssure
flu
ctu
ation in S
/T.
Incre
ase
S/T
oil
pre
ssu
re. ***
Re
-fill
oil
in F
WD
se
al, w
he
ne
ver
is n
ecessa
ry.
Ye
s
TU
Oil
pip
e join
tO
il le
akage
Loose join
tR
ep
air p
ipe
jo
ints
.
CU
Level gauge
Oil
level in
cre
ases o
ver
2L/d
ay.
Leakage fro
m the #
3 s
eal ri
ng
Activa
te t
he
#3
S s
ea
l rin
g.
Ye
s
FW
D
se
al
Level gauge
Oil
level in
cre
ases o
ver
2L/d
ay.
Leakage fro
m the #
4 s
eal ri
ng
Re
co
ve
ry. R
ep
air t
he
#4
se
al rin
g.
Ye
s
Co
ntin
uo
us s
eaw
ate
r re
cove
ry.
Fill
ed
with
se
aw
ate
r in
a d
ay.
Da
ma
ge
of
the
#1
& 2
se
al rin
gs
Incre
ase
air f
low
ra
te a
t 6
0－
80
L/m
in.
Co
nd
uct d
ive
r in
sp
ectio
n.
Re
pa
ir A
FT
se
al.
Ye
s
Re
co
ve
ry o
f o
il o
ver
2L
/day
Da
ma
ge
of
the
#3
se
al rin
gA
ctiva
te t
he
#3
S s
ea
l rin
g.
Ye
s
5.2
Ala
rms &
Acti
on
s
***
Incre
ase
oil
pre
ssu
re b
y o
pe
ratin
g A
ir R
ea
ly “
AR
1” o
n M
U.
T
he d
iffe
rtia
l pre
ssure
"P
s/t -
Pd"
should
not exc
eed 0
.05M
Pa. (S
ee P
. 7 C
alc
ula
tion o
f pre
ssure
s)
A1
(MU
)
Air
pre
ssure
Low
MU
Air
So
urc
e
A2
（T
U）
Oil
Level
Hig
hA
FT
se
al d
am
ag
e
Incre
ase
air f
low
ra
te a
t 6
0－
80
L/m
in.
Co
nd
uct d
ive
r in
sp
ectio
n.
Re
pa
ir A
FT
se
al.
Ye
s
A2
（T
U）
Oil
Level
Low
A3
（C
U）
Liq
uid
Level
Hig
h
CU
Level G
auge
Dra
in
- 12 -
5.3
Oth
er
ab
no
rma
liti
es
& A
cti
on
s
Ab
no
rma
litie
sC
heck P
oin
tP
ossib
le C
ause
Action
sR
ep
ort
to
KE
ME
L
Sea
wa
ter
pen
etr
atio
nin
toste
rntu
be
with n
o s
ea
wa
ter
colle
cte
d in
CU
.
Air p
ressu
re in C
U.
Ste
rn tu
be
oil
con
ditio
n.
Blo
ckad
e in
dra
in p
ipe.
Incre
ase
air flo
w r
ate
at 6
0－
80L
/min
.
Cle
an p
ipe
by u
sin
g F
resh
Wa
ter
Lin
e in
MU
.
Conduct div
er
inspection, if n
ecessary
.
Yes
Ste
rntu
be
oil
leak
with
no
colle
ction
of o
il in
CU
.
Pre
ssure
in
CU
.
Oil
leve
l in
TU
.
Bro
ke
n p
ipe
in s
tern
tu
be
Blo
ckag
e in
dra
in p
ipe.
Activa
te t
he
#3
S s
ea
l rin
g a
nd
ke
ep
mo
nito
rin
g.
Cle
anin
g A
ir p
ipe b
y F
resh
Wate
r.Y
es
Air
pre
ssure
hig
ha
larm
(Optio
n)
from
A1.
Va
lve
po
sitio
n o
n A
ir B
low
Lin
e.
P4 p
ressure
on M
U.
Va
lve
s r
em
ain
clo
se
d.
Blo
ckad
e in
Air B
low
Lin
e.
Ope
n t
he
va
lve
s.
Cle
an p
ipe
by u
sin
g F
resh
Wa
ter
Lin
e in
MU
.Y
es
Cle
an
ing
Air
Pip
eb
yF
res
hW
ate
rIn
case
P4
pre
ssure
be
com
eh
ighe
rth
an
Pd
over
0.0
3M
Pa
dif
fere
nce
,it
isp
ossib
leth
at
air
flow
pip
es
sta
rte
dto
hav
eb
loc
kage
due
toe
xtr
ac
tion
of
salt
etc
.M
Uh
as
afr
esh
wate
rline
todis
solv
eth
eblo
ckage
an
dto
cle
an
the
pip
e.
Itis
recom
mended
that
the
sh
ipcle
an
the
pip
eb
yu
sin
gth
elin
ew
ith
6m
on
ths
inte
rvals
.
Pro
ce
du
refo
rF
res
hW
ate
rC
lea
nin
g(T
obe
done
wh
ileM
/Esto
pped
or
on
turn
ing
gear.
)1)
Op
en
dra
invalv
eon
CU
.2)
Turn
3-W
ay
Valv
ein
MU
,to
the
direction
ofF
resh
Wate
rLin
e.
-N
ote
13)
Op
en
the
valv
eand
sta
rtsupply
fresh
wa
ter.
4)
Cle
an
the
air
pip
etill
fresh
wate
rcom
ing
outfr
om
the
dra
invalv
eon
CU
.-
No
te2
5)
Sto
pfr
esh
wate
rsupply
.6)
Tu
rn3-W
ay
Va
lve
inM
U,to
the
direction
ofA
irB
low
Lin
e.
7)
Clo
se
the
dra
invalv
eon
CU
after
blo
win
goutw
ate
rby
the
air.
8)
Exa
min
ea
llp
ressure
sand
air
flow
bein
gin
norm
al
conditio
n.
Note
1.
When
3-w
ay
Valv
eis
turn
ed
toth
edirection
of
Fre
sh
Wate
r,A
irB
low
line
isshut
off
an
dair
pre
ssure
set
by
R1
isdirectly
giv
en
toT
U.
This
may
cause
activ
atio
nof
Safe
tyR
elie
fVa
lve
on
TU
,w
hic
his
not
harm
ful.
Th
eactiva
tion
ofS
afe
tyR
elie
fVa
lve
ma
ybe
sto
pp
ed
by
reducin
gR
1settin
gduri
ng
Fre
sh
Wate
rC
leanin
g.
How
eve
r,do
not
red
uce
R1
sett
ing
in
case
of
contin
ual
seaw
ate
rle
aka
ge
into
CU
.Als
om
ake
sure
R1
should
be
back
toth
esetva
lue
after
the
cle
anin
g.
Note
2.
Itta
kes
atim
eto
have
cle
an
ing
wate
rcom
ing
out
at
CU
dra
in.
(Flo
wC
ontr
ol
Valv
eo
nfr
esh
wate
rlin
eis
initi
ally
set
and
locke
dat
very
slo
wspeed
so
that
the
wate
rd
oes
no
tpenetr
ate
into
ste
rntu
be
by
sudden
rise
of
wate
rpre
ssure
.In
case
the
initi
al
settin
gis
lost,
fully
clo
se
the
contr
olva
lve
then
turn
the
wheel
180
degre
e,
half-
turn
,fo
rre
-settin
g.
- 13 -
CU OU X-line
Valve V11 E F A B Air Vent I GOperation Close Close Close Close Close Open Open Open
X-line OU CU
Valve G I Air Vent B A F E V11
Operation Close Close Close Open Open Open Open Open
TU MU
Valve Operation for switching to X-line
MU TU
Note 1. V11 valve is located in MU, on the line to pressurize TU.
Note 2. Confirm detail valve operation in Finished Plan - Piping Diagram Fig. 2.
Valve Operation for switching back to Air Seal
6. Switch-over to Oil Seal System for emergency
Losing air supply to AFT seal causes oil pressure drop in stern tube. In case of air lost while the vessel is at sea,
immediately examine seawater penetration in CU. It is possible to operate the system without air if no seawater is
observed in CU. Air supply, however, should be recovered to raise the oil pressure at the earliest possible. During
the operation with no air, keep monitoring CU by frequent examination of the drain. In case no air supply to MU may
continue for a long period, study possibilities of slow-down or stop M/E till air supply is recovered.
If seawater continuously fills CU in a short time, conduct protection of stern tube bearing from seawater by switching
Air Seal system over to normal oil seal system as per the procedures below,
1) Switch-off all alarms on MU, TU and CU and stop air supply.
2) Stop OU, and then take action 3) with no delay.
3) Change oil circulation l via X-line as per “Valve Operation for switching to X-line” shown below
4) Re-start OU with no delay.
While operation with X-line, keep OU running all the time to maintain the oil head pressure which minimizes the
chance of seawater penetration into stern tube. Strengthen examination of stern tube oil drain and remove
contaminated oil when it is found. It is necessary to recover air source failure as soon as possible. At the same time,
investigate possibility of earlier inspection and repair of AFT seal for seawater leakage.
- 14 -
7. Operation for Dry-docking, Undocking and Laying-up
7.1 Dry-docking & Undocking
In case of dry-docking and undocking, shut-down and re-start Air Seal system as the manners below,
1) Stop all alarms on MU, TU and CU, and then stop air supply to CU to shut-down before entering dock.
2) Discharge oil in stern tube, AFT seal and FWD seal for seal repair after dry-up.
3) Carry out inspection or repair of the seal unit as necessary.
4) Fill stern tube and carry out oil pressure test as necessary. (See P. 6 for oil filling and pressure test.)
5) Re-start the system before undocking. (See articles 2 & 3 for the procedures.)
7.2 Laying-up
In case of laying-up the ship with no power and no air, shut-down Air Seal system as the manners below,
1) Stop all alarms on MU, TU and CU.
2) Stop OU to shut-down the system.
3) Examine existence of seawater in CU through the drain valve.
4) In case of no seawater observed, carry out drain check once a week after the shut-down.
5) In case seawater fills CU in a short time, conduct protection of stern tube bearing from seawater by switching Air
Seal system over to normal oil seal system using X-line as per article 6.
6) Circulate stern tube oil via X-line by operating OU.
7) Check oil pressure at Ps/t gauge.
8) Stop OU to shut-down the system.
9) Confirm the oil head is maintained.
10) Examine Ps/t once a week and stern tube drain.
11) Recover the pressure by the procedures 6) – 9), if necessary.
Re-start Air Seal after the laying-up period as the manners below,
1) Operate the valves as per article 6 “Valve operation for switching back to Air Seal”.
2) Confirm drain valve on CU is closed.
3) Operate OU.
4) Supply air to MU and activate all alarms on MU, TU and CU to re-start.
5) Examine all pressures and air flow of the system.
It is possible that marine growths around AFT seal area during laying-up period may cause reduction of seal tightness. Recommend cleaning
and overhaul inspection of the seal at the earliest opportunity after re-activation of the system.