Wartsila ?31DF Series Product Manual page 131

Wärtsilä 31DF Product Guide
Each engine must have its own vent pipe into open air. The crankcase ventilation pipes may
not be combined with other ventilation pipes, e.g. vent pipes from the system oil tank.
The diameter of the pipe shall be large enough to avoid excessive back pressure. Other possible
equipment in the piping must also be designed and dimensioned to avoid excessive flow
resistance.
A condensate trap must be fitted on the vent pipe near the engine.
The connection between engine and pipe is to be flexible. It is very important that the crankcase
ventilation pipe is properly fixed to a support rigid in all directions directly after the flexible
hose from crankcase ventilation outlet, extra mass on the oil mist detector must be avoided.
There should be a fixing point on both sides of the pipe at the support. Absolutely rigid mounting
between the pipe and the support is recommended. The supporting must allow thermal
expansion and ship's structural deflections.
Design data:
Flow
Backpressure, max.
Temperature
Fig 7-5
DBAE248994
Condensate trap (DAAF369903)
see Technical data
see Technical data
80°C
The size of the ventilation pipe (D2) out
from the condensate trap should be
equal or bigger than the ventilation pipe
(D) coming from the engine.
For more information about ventilation
pipe (D) size, see the external lubricating
oil system drawing.
The max. back-pressure must also be
considered when selecting the ventilation
pipe size.
7. Lubricating Oil System
7-9