Fuel systems

Heavy Fuel Oil (HFO) and Low Sulfur Heavy Fuel Oil (LSFO), intended for all users on board. It is kept in 3 types of fuel tanks: storage tank, settling tank and daily tank (see in the Figure). Fuel can be pumped from bunker tanks to HFO and LSFO settling tanks. In these tanks, the fuel is allowed to settle before being cleaned by fuel separators. The fuel purified by the separators is fed to HFO and LSFO daily. From these tanks, HFO is supplied to the main engine, generators, and boilers. HFO and Diesel Oil storage tanks are filled using a bunker filling pipeline and connection stations on the port and starboard sides of the vessel. The DO fuel is stored in tanks.

Sampling valves are installed (continuous dripping sample valve can be installed only during bunkering, between flanges of bunker pipe and bunker hose of bunker barge) at each pipe fuel connection station in front of each bunker manifold valve. Bunker lines are fitted with pressure valves which, when actuated, release fuel into the fuel (FO) overflow tank.

There is one HFO transfer pump used to pump HFO from the storage tanks to the HFO settling tanks or between HFO bunker tanks. The Diesel Oil transfer pump is designed to pump DO from the DO storage tank to the DO daily tank. If one of the pumps fails, the other can be used. For this purpose, it is necessary to remove both blinds between the HFO and DO fuel storage systems. The HFO transfer pump can be started and stopped automatically using HFO settling tank level switches. Subsequently, the settled fuel from the HFO settling tank is transferred to the HFO service tank with HFO separators.

The DO transfer pump is started and stopped manually, depending on the fuel level of the DO daily tank. However, under normal circumstances, it is better to supplement the DO daily tank with a DO separator.

The fuel system includes an FO overflow tank to collect any overflow from the FO storage and settling tanks in the event of an overfill. When the daily tanks are overfilled, the fuel spills into the settling tanks. Only the overfilled fuel from the daily service tanks of the emergency generator diesel and inert gas generator is transferred to the diesel storage tank. DO and HFO pipeline safety valves of storage, when the specified pressure is exceeded, it also drains the fuel into the fuel tank and reduces the pressure in the system. The overflow tank contains high and dangerously high-level alarms to warn of excess fuel level in the tank. HFO transfer pump is used to pump the contents of the overflow tank into the HFO storage tanks or into the HFO settling tank.Using any transfer pump and bunker refill line, fuel oil can be pumped from one bunker tank to another.

All fuel outlet valves from fuel tanks are remotely controlled quick-closing valves. They are controlled remotely from the fire control station. Valves that are closed after actuation must be reopened manually at the installation site. Fuel settling and daily tanks have self-closing valves to check and drain water condensate. Water condensate, dirt or other liquids entering the FO tank are discharged through these water condensate check valves.

All fuel tanks have local and remote temperature gauges. The remote temperature meters transmit the information to the Engine control room (ECR).

All HFO tanks have a heating pipe to which the heating steam is supplied from the steam system. Also, the entire HFO transfer pipeline is heated by steam.

NOTE: all fuel bunkering and pumping operations must be performed properly in accordance with company policy and requirements.