8.3.2 Oil and water separator (3S01)
An oil and water separator should always be installed in the pipe between the compressor and the air vessel.
Depending on the operation conditions of the installation, an oil and water separator may be needed in the
pipe between the air vessel and the engine.
8.3.3 Starting air vessel (3T01)
The starting air vessels should be dimensioned for a nominal pressure of 3 MPa.
The number and the capacity of the air vessels for propulsion engines depend on the requirements of the
classification societies and the type of installation.
It is recommended to use a minimum air pressure of 1.8 MPa, when calculating the required volume of the
vessels.
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.
Figure 8.4
Starting air vessel
Weight
[kg]
Dimensions [mm]
Size
[Litres]
D
L3
1)
L2
1)
L1
274
480
110
243
1767
250
450
480
133
243
3204
500
625
650
133
255
2740
710
810
650
133
255
3560
1000
1)
Dimensions are approximate.
The starting air consumption stated in technical data is for a successful start. During a remote 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 remote 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 as remote
starts, usually so that only the last starting attempt is successful.
The required total starting air vessel volume can be calculated using the formula:
where:
total starting air vessel volume [m
3
]
V
R
=
normal barometric pressure (NTP condition) = 0.1 MPa
p
E
=
air consumption per start [Nm
3
] See Technical data
V
E
=
Product Guide Wärtsilä 34DF - 3/2012
83
Product Guide
8. Compressed Air System
