1. NFPA 31 Standard for the installation of Oil- Burning Equipment
Oil Heat
NFPA 31
Standard for the installation of Oil- Burning Equipment

2. Origin and Development of NFPA 31
Oil burning equipment standards date back to 1902, when they were issued by the National Board of Fire Underwriters under the title “ Rules and requirements of the National Board of Fire Underwriters for storage and use of Fuel Oil and for the construction and Installation of Oil Burning Equipment”
In 1913, the project was turned over to the NFPA and a completely revised standard was presented.
The following are sections from that code book:

3. Chapter 3: Definitions
General: The definitions contained in this chapter shall apply to the terms used in this standard. Where terms are not defined in this chapter or within another chapter, they shall be defined using their ordinarily accepted meanings within the context in which they are used.
NFPA Official Definitions:
BTU- Abbreviation for British Thermal Unit. The quantity of heat needed to raise the temperature of 1 pound of water, 1 degree.

4. Boiler- A closed vessel in which water is heated, steam is generated, steam is superheated, or in which any combination thereof takes place by the appliance of heat from combustible fuels, in a self-contained or attached furnace.
High Pressure Boiler- A boiler for generating steam at gauge pressure in excess of 15 psi, or for heating water to a temperature in excess of 250 degrees, or at a gauge pressure in excess of 160 psi.
Hot water supply boiler- A low pressure hot water boiler having a volume exceeding 120 gal, or a heat input exceeding 120 gal, or a heat input exceeding 200,000 Btu/hr, or an operating temperature exceeding 200 degrees that provide hot water to be used outside the boiler.

5. Low pressure boiler – A boiler for generating steam at gauge pressure not in excess of 15 psi, or for furnishing water at a maximum temperature of 250 degrees at a maximum gauge pressure of 160 psi.
Tanks:
Oil Burner Auxiliary Tank- A tank having a capacity of not more than 60 gallons that is listed for installation in the supply piping between a burner and its main fuel tank.
Oil Burner Gravity Tank- A supply tank from which the oil is delivered to the burner by gravity.
Oil Burner Storage Tank: A separate tank that is not connected directly to the oil burning appliance.

6. Chapter 5: Air for Combustion and Ventilation
5.1 Scope: This chapter shall apply to those requirements necessary to ensure that adequate air for safe combustion is provided for oil-burning appliances and equipment.
Basic Requirements: Oil burning appliances and equipment shall be installing in locations where available ventilation permits satisfactory combustion of oil, proper venting of combustion gases, and maintenance of safe ambient temperatures under normal conditions of use.

7. 5.4.1 All air taken from inside the building
– The confined space shall be provided with two permamemt openings as shown. One near the bottom and one near the top.
Each opening shall have a free area of not less than 1 square inch per 1000 BTU/hr, based on the total input rating of all appliances in the space.
Each opening shall freely communicate with interior areas of the building that, in turn, have adequate infiltration from the outside.

8. 5.4.2 All air taken from Outdoors
The confined space shall be provided with two permanent openings, one in or near the top of the space and one near the bottom.
The opening shall communicate directly or by means of ducts with the outdoors or to spaces, such as attics or crawl space, that themselves freely communicate with the outdoors.

9. Chapter 8: Heating Fuel Piping Systems and Components
A readily accessible fusible link safety shutoff valve that closes against the supply pressure shall be installed at each of the following points:
Within 6 inches of the filter on the tank side of the filter
Within 12 inches of the inlet connection to the burner.
Pressure testing for leakage shall be conducted with air or inert gas and shall be held for a time sufficient to conduct a complete visual inspection of all piping and fittings, but in no case for less than 10 minutes after stabilization.

10. 8. 11. 3. 1- A gauge pressure of at least 5
A gauge pressure of at least 5.0 psi, but not more than 10 psi, shall be applied to all portions of the supply piping to be evaluated.
Leakage shall be detected by the appearance of bubbles after a soap and water solution or an equivalent leak detection fluid has been sprayed onto all joints.
Vacuum testing for leakage shall be conducted with a vacuum pump and vacuum gauge with .5 in Hg increments and accuracy of at least 2%. Vacuum shall be held for at least 30 minutes after stabilization with no loss.

11. A vacuum of at least 20 in Hg shall be applied to all portions of the supply piping to be evaluated.
Leakage shall be determined by any loss of vacuum after the test time.
Gauges used for leak testing shall be suitable for the test type, shall be in working order, and shall be calibrated. Gauges shall have a test range of not more than twice the test pressure and shall indicate in increments of not more than 1.0 psi.

12. 8.5 Tank Fill Piping
The fill pipe connected to the tank shall be large enough and so located as to permit readily filling in a manner that minimizes spills. The fill pipe shall also be:
At least 1 ¼” nominal pipe size
Pitched toward the tank
Protected from physical damage
Without sags or traps where liquid can collect.
For tanks that directly supply a fuel-burning appliance and are intended to be filled by hose from a delivery vehicle, the fill pipe shall terminate as follows:
Outside the building at a point at least 2 ft from any building opening.
In a manner that prevents spills when the filling hose is disconnected.