Wartsila ?31DF Series Product Manual page 79

Wärtsilä 31DF Product Guide
System
Starting air
Cooling water
Exhaust gas
Charge air
1)
In case of carbon steel pipes
Methods applied during prefabrication of pipe spools
A = Washing with alkaline solution in hot water at 80°C for degreasing (only if pipes have been greased)
B = Removal of rust and scale with steel brush (not required for seamless precision tubes)
D = Pickling (not required for seamless precision tubes)
Methods applied after installation onboard
C = Purging with compressed air
F = Flushing
5.7.2 Fuel oil pipes
Before start up of the engines, all the external piping between the day tanks and the engines
must be flushed in order to remove any foreign particles such as welding slag.
Disconnect all the fuel pipes at the engine inlet and outlet . Install a temporary pipe or hose
to connect the supply line to the return line, bypassing the engine. The pump used for flushing
should have high enough capacity to ensure highly turbulent flow, minimum same as the max
nominal flow. Heaters, automatic filters and the viscosimeter should be bypassed to prevent
damage caused by debris in the piping. The automatic fuel filter must not be used as flushing
filter.
The pump used should be protected by a suction strainer. During this time the welds in the
fuel piping should be gently knocked at with a hammer to release slag and the filter inspected
and carefully cleaned at regular intervals.
The cleanliness should be minimum ISO 4406 (c) 20/18/15, NAS9. A measurement certificate
shows required cleanliness has been reached there is still risk that impurities may occur after
a time of operation.
Note! The engine must not be connected during flushing.
5.7.3 Lubricating oil pipes
Flushing of the piping and equipment built on the engine is not required and flushing oil shall
not be pumped through the engine oil system (which is flushed and clean from the factory).
It is however acceptable to circulate the flushing oil via the engine sump if this is advantageous.
Cleanliness of the oil sump shall be verified after completed flushing and is acceptable when
the cleanliness has reached a level in accordance with ISO 4406 (c) 21/19/15, NAS10. All
pipes connected to the engine, the engine wet sump or to the external engine wise oil tank
hall be flushed. Oil used for filling shall have a cleanliness of ISO 4406 (c) 21/19/15, NAS10.
Note! The engine must not be connected during flushing
5.7.4 Pickling
Prefabricated pipe spools are pickled before installation onboard.
DBAE248994
Methods
A,B,C
A,B,C
A,B,C
A,B,C
5. Piping Design, Treatment and Installation
5-5