Wartsila ?31DF Series Product Manual page 137

Wärtsilä 31DF Product Guide
The starting air vessels are to be equipped with at least a manual valve for condensate drain.
If the air vessels are mounted horizontally, there must be an inclination of 3...5° towards the
drain valve to ensure efficient draining.
Fig 8-2
The starting air consumption stated in technical data is for a successful start. During start the
main starting valve is kept open until the engine starts, or until the max. time for the starting
attempt has elapsed. A failed start can consume two times the air volume stated in technical
data. If the ship has a class notation for unattended machinery spaces, then the starts are to
be demonstrated.
The required total starting air vessel volume can be calculated using the formula:
where:
V
p
V
p
Rmax
p
Rmin
DBAE248994
Starting air vessel
= total starting air vessel volume [m
R
= normal barometric pressure (NTP condition) = 0.1 MPa
E
= air consumption per start [Nm
E
n = required number of starts according to the classification society
= maximum starting air pressure = 3 MPa
= minimum starting air pressure = See Technical data
1) Dimensions are approximate.
3 ]
3
] See Technical data
8. Compressed Air System
8-3