Oil In Cascade Tank (Hot well) Cause And Action


  • Most probable cause is leaky fuel oil heaters. Any leaks in oil heaters leads oil in cascade tank.
  • Deck cargo tank steam line leak


  • Reduce load on boiler
  • Keep a watch on Observation tank oil level
  • With proper PPE Open top cover of Cascade tank.
  • If less oil, drain it from top or add a chemical that breaks the oil infine particles.
  • If more oil, manually remove it by absorband pads or remove it by weldon pump from top.
  • In no case emulsified water to go in boiler.
  • Once leak identified shut down boiler if necessary.
  • Shut the I/L valve to Atm. Condensor.
  • Check Atm.Condensor drain for oil traces in atm. Condensor. If yes flush it completely.
  • Check boiler water condition from sampling line. Find out if any oil present in boiler.If yes Do a Scum blow down.
  • Take a sample again, if oil traces that means boiler too much contaminated, then completely blow down the boiler.
  • Make sure Of MARPOL ANNEX 1 in this case.
  • Oil content to be <15 ppm Or We would have to drain in Bilges or Collect it in a seperate drum then give it to Port reception.
  • Flush clascade tank after cleaning
  • Flush Boiler with FW
  • Check cascade water samples
  • Once all samples ok Take water in cascade tank
  • Take water in boiler
  • Do Cold firing
  • Increase the load slowly
  • See how much time it takes for the steam to rise.
  • If it takes more time, that means oil is still present and will take more time to raise steam.
  • Proceed further according to action req.

How to Find Out Leaks

  • If ER leak check heaters= open heater drains and confirm.
  • If ER tanks heaters leak = open the steam trap drain and confirm.
  • If Deck cargo tank steam lines leak = open return lines and check on deck.
  • If a Observation tank is given on deck, then check there.