How to - Aux Engine HFO to DO Change and Back

Aux engines fuel change over from HFO to DO 

Close the steam heating for the aux engines heater located in the aux. engine room.

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Put the viscometer into manual mode and monitor the temperature drop on it

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When the fuel temperature drops to 90˚C, change over fuel supply three way valve A5; make sure the valve A2 is open.

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Wait around 10 minutes before you change over fuel return three way valve A6 in order to avoid the diesel oil service tank 11P contamination with heavy fuel.

Aux engines fuel change over from DO to HFO    

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Change over three way valve A6 fuel return so the DO service tank 11P does not get contaminated with HFO. Change over three way valve A5 fuel supply. Monitor the fuel temperature on the viscometer in the control room. Wait around 10 minutes before opening the steam valves for the heater and slowly start increasing the temperature (this is to avoid diesel oil from being gassed due to increase in temperature which would get gas before entering to engine fuel pumps) When desired temperature and viscosity is reached, set viscometer to “auto”.