FUEL OIL SYSTEM FROM SETTLING TANK TO BURNER - BOILER



1. Oil is pumped into the settling tanks, and any water allowed to settle out. 

2. When required for use, the high suction valve on the settling tank is opened and oil allowed to pass to the cold filters fitted on the suction side side of the fuel oil service pump.


3. A spring-loaded relief valve fitted on the discharge side of the pump allows any excess oil to spill back to the suction side of the pump in the event of overpressure.

4. After leaving the pump, the oil temperature is raised in a fuel oil heater. This is done in order to lower the viscosity of the oil, making it easier to filter and finally to atomize.

5. The correct oil temperature is maintained by means of a thermostat placed in the outlet from the fuel oil heater, which controls the supply of steam to the heater.

6. The hot filters fitted after the heater are normally of an auto-clean type. These filters provide a fine filtration. This prevents wear and chokage of the fine passages in the atomizing tip of the fuel oil burners.

7. The heated and filtered oil now passes through an automatic pneumatically- operated control valve which varies the oil supply pressure to the burners in response to variations in the main steam pressure transmitted to a master pressure controller.


8. The combustion air controller also varies in order to maintain the correct ratio between the amounts of fuel and air supplied to the furnace.

9. Two emergency valves are now fitted -: 

- The first is a manually-operated quick shut off valve which enables the fuel oil to be shut off by hand from the boiler very rapidly in case of emergency.

-  The second is a shut off valve with a steam actuator which
operates to shut off the fuel oil in the event of loss of water in the boiler.

10. The oil is now ready to enter the individual dead legs supplying oil to the burners.

11. All necessary pressure gauges, thermometers, air vents, etc. must be fitted for the proper operation of the system.

12. Safety fittings include quick closing valves-operated from outside the engine-room-fitted to the suction lines from the settling tanks, which enable fuel to be shut off from the system in case of emergency. 

13. There is also an emergency stop fitted to the fuel oil service pump.

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