Wartsila ?31DF Series, Product Manual

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7.2.4 Pre-lubricating oil pump (2P02)
The pre-lubricating oil pump is a scew or gear pump, which is to be equipped with a safety
valve.
The installation of a pre-lubricating pump is mandatory. An electrically driven main pump or
standby pump (with full pressure) may not be used instead of a dedicated pre-lubricating
pump, as the maximum permitted pressure is 200 kPa (2 bar) to avoid leakage through the
labyrinth seal in the turbocharger (not a problem when the engine is running). A two speed
electric motor for a main or standby pump is not accepted.
The piping shall be arranged so that the pre-lubricating oil pump fills the main oil pump, when
the main pump is engine driven.
The pre-lubricating pump should always be running, when the engine is stopped.
Depending on the foreseen oil temperature after a long stop, the suction ability of the pump
and the geometric suction height must be specially considered with regards to high viscosity.
Design data:
see Technical data Capacity
350 kPa (3.5 bar) Max. pressure (safety valve)
100°C Design temperature
500 cSt Viscosity for dimensioning of the electric
motor
7.2.5 Pressure control valve (2V03)
Design data:
1.0 MPa (10 bar) Design pressure
Difference between pump capacity and oil flow through engine Capacity
100 °C Design temperature
7.2.6 Lubricating oil pump, stand-by (2P04)
The stand-by lubricating oil pump is normally of screw type and should be provided with an
safety valve.
Design data:
see Technical data Capacity
0.8 MPa (8 bar) Design pressure, max
100°C Design temperature, max.
SAE 40 Lubricating oil viscosity
500 mm
2
/s (cSt) Viscosity for dimensioning the electric
motor
7.3 Crankcase ventilation system
The purpose of the crankcase ventilation is to evacuate gases from the crankcase in order to
keep the pressure in the crankcase within acceptable limits.
7-8 DBAE248994
Wärtsilä 31DF Product Guide 7. Lubricating Oil System