1. Oil Heat
Properties of Fuel Oil

2. Fuel oil is the only liquid fuel used for residential and light commercial heating.
It is refined from petroleum and is called a “distillate” because it is distilled from crude oil.
Six fuel oils are in common use: No.’s 1,2,4,5L,5H, and 6.
All these fuels vary greatly among one another, and only one is used for residential and light commercial heating: No.2 fuel oil.

3. It is good to be aware of the other fuel oils, but you don’t need to have a great amount of knowledge of them for most residential and light commercial work.
The properties of oil determines the grade and the reason a particular fuel oil is chosen for a specific application.

4. Fuel oil is broken down into different properties:
They are:
Heating value
Carbon- hydrogen content
Flash point
Viscosity
Carbon residue
Water and sediment
Pour point
Ash content
Distillation quality

5. Heating Value
The heating value of the oils varies from approximately 135,00 btu’s/per gallon for no.1 oil
Approximately 153,000 btu’s/per gallon for no.6 fuel oil.
No. 2 oil has a heating range of 137,000 to 140,000 btu/per gallon.

6. Heating Value of No.2 Fuel Oil
140,000 Btu’s
1 Gallon of No.2 Fuel Oil

7. Carbon-Hydrogen Content
Fuel oils are made of carbon and hydrogen.
A chemical formula tells us the carbon-hydrogen relationship.
No.2 fuel oil contains approximately 85% carbon and 15% hydrogen.
The more carbon the oil contains, the more heating value it contains.
The higher number oils, like No.6 may contain 88% carbon. These oils are also called “heavy oils” because they weigh more than the other oils.

8. No. 2 oil weighs from 6. 96 to 7. 29 pounds per gallon, and No
No.2 oil weighs from 6.96 to 7.29 pounds per gallon, and No. 6 oil weighs around 8.05 to 8.44 pounds per gallon.
No.2 oil
6.96 to 7.29 pounds
No. 6 oil
8.05 to 8.44 pounds

9. Flash point
The flash point involves the storage and handling of the fuel oil.
All liquid fuels have a maximum safe storage and handling temperature.
The flash point is the lowest temperature at which vapors above the fuel oil ignite in the air when exposed to a flame.
The lighter the oil, the lower the flash point, and the lower the maximum storage temperature must be.

10. Viscosity
Viscosity is the thickness of the oil under normal temperatures.
This thickness determines the size of the metering device used to govern the amount of fuel flowing to an oil burner.
Since the heavier oils are thicker, they require larger metering devices

11. Viscosity is expressed in “Saybolt Universal Viscosity seconds” (SUS), which describes how much oil will drip through a calibrated hole at a certain temperature.
As the temperature drops on a certain oil, the thicker it will become, causing the oil to drip through the calibrated hole less and less.

12. Carbon Residue
A carbon residue test can be performed on an oil sample by vaporizing a known weight of the oil in a process in which oxygen is absent.
The remaining carbon residue is measured.
If the oil is being burned properly, it will not leave any carbon residue.

13. Water and sediment content
The fuel oil should be refined and delivered with a minimum of water and sediment.
To much sediment plugs up filters and strainers.
Water in the oil causes poor flame characteristics and burning problems. It also corrodes the inside of the fuel containers and pipelines that are made of steel and iron.

14. Corrosion can loosen and get lodged in strainers and filters, and in cold climates, it can freeze and block the flow of oil.
Refineries, and distributor’s are responsible for caring for and delivery of clean, dry oil.

15. Pour point
Pour point is the lowest temperature at which the fuel can be stored and handled.
No.2 fuel oil is one of the lower pour point fuels
Which means, that it can be used at lower temperatures and stored outside.
Heavier fuel oil are more sensitive to cold and become thick when exposed to low temperatures.

16. Ash content
The ash content of fuel oil indicates the amount of non combustible materials in the fuel oil.
These materials pass through the flame without burning and are contaminants.
They can be abrasive and wear down burner components.
The refinery is responsible for keeping the ash content within the required tolerance.

17. Distillation Quality
Oil must be turned into a vapor before it can be burned.
The distillation quality describes the ability of the oil to be vaporized.