Marine Installation Manual
2021-08
4-28
4 Ancillary Systems
4.3 Lubricating oil systems
X72DF
4.3.7
Drain tank
The engine is designed to operate with a dry sump: the oil returns from the bear
-
ings, flows to the bottom of the crankcase and through strainers into the lubri
-
cating oil drain tank. The drain connections from the crankcase to the drain tank
are arranged vertically.
The drain tank is to be located beneath the engine and equipped with the fol
-
lowing:
•
Depth sounding pipe
•
Pipe connections for lubricating oil purifiers
•
Heating coil adjacent to pump suction
•
Air vents with flame protection
There is to maintain adequate drainage under sea conditions resulting in pitching
and rolling. The amount of lubricating oil required for an initial charge of the
drain tank is indicated in
. The total tank size is normally 5-10%
greater than the amount of lubricating oil required for an initial filling.
Figure 4
-
14 Dimensioning and filling process of lubricating oil drain tank
NOTE
The classification societies require that all drain pipes from the crank
-
case to the drain tank are taken as low as possible below the free sur
-
face of the oil to prevent aeration and foaming; they have to remain
below the oil surface at all times.
Strict attention has to be paid to this specification.
SM-0037
d
DN
h2
h
h1
Suction area
Distance between suction pipe and bottom of tank
*1)
First filling
h1
h2
LO pump stopped
hx
h2
After system
commissioning
LO pump stopped
Second filling
h1
h2
LO pump stopped
LO pump in operation
h2
operating level
Engine in operation
Level after filling of external system.
Volume and level in the lub. oil drain tank depend on capacity of pipes, coolers, filters, etc.
The oil volume in tank contains part of the oil quantity which drains back when the pumps
are stopped.
*1)
