Changeover from HFO to MGO

Can anybody share any tips for the safe changeover of Main Engine and Diesel Generators from HFO to MGO?


Hello, please find here below the recommended HFO to MGO change over procedure according to many marine diesel engines.makers

  1. Ensure that the temperature of the MGO in the service tank is on an acceptable level
    regarding the expected viscosity at the engine inlet
  2. Reduce the engine load
  • The load during this process should be 25 ~ 40% to ensure a slow reduction of the
  • The load can, based on experience, be changed to a higher level – up to 75% as
    described in operation book
  1. Stop steam tracing and steam to pre-heater
  2. Carry out change-over of fuel when the fuel temperature starts to drop
  3. Please note that a complete change-over (only MGO in the system) can take several
    hours depending on the engine load, volume of fuel in the circulating circuit and the
    system layout
    In general, only the viscosity controller should control the steam valve for the fuel oil heater.
    However, observations of the temperature/viscosity must be the factor for manually taking
    over the control of the steam valve to protect the fuel components. Using a refractometer to measure the temperature on the Fuel Pumps body throughout the process can be considered as a good preventive measure.
    Two things to be kept under observation during the change-over are:
    a) The viscosity must not drop below 2 cSt and not exceed 20 cSt.
    b) The rate of temperature drop of the fuel inlet to the fuel pumps must not exceed