WÄRTSILÄ 46F Series, Product Manual

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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:
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
=
required number of starts according to the classification society n =
maximum starting air pressure = 3 MPa p
Rmax
=
minimum starting air pressure = See Technical data p
Rmin
=
NOTE
The total vessel volume shall be divided into at least two equally sized starting air
vessels.
8.3.4 Air filter, starting air inlet (3F02)
Condense formation after the water separator (between starting air compressor and starting
air vessels) create and loosen abrasive rust from the piping, fittings and receivers. Therefore
it is recommended to install a filter before the starting air inlet on the engine to prevent particles
to enter the starting air equipment.
An Y-type strainer can be used with a stainless steel screen and mesh size 400 µm. The
pressure drop should not exceed 20 kPa (0.2 bar) for the engine specific starting air
consumption under a time span of 4 seconds.
8-8 DAAB605814
Wärtsilä 46F Product Guide 8. Compressed Air System