Town of Darien
Installation Requirements for Fuel Oil Tanks
A PERMIT FOR INSTALLATION SHALL BE TAKEN OUT PRIOR TO BEGINNING WORK!!
All Fuel Oil Tank
installations shall comply with N.F.P.A. Standard 31, 1992 Edition.
Tanks for underground
use shall comply with the construction provisions of Standard UL 58, UL 1316 or
ASTM D4021.
Tank(s) may be within 1 foot of foundation if excavation does not exceed depth of footings. If lower than footings tank must be a minimum of 5 feet from the foundation.
Tank(s) must be a minimum of 1 foot from the property line.
Tank(s) shall be set on a firm foundation and surrounded with at least 6 inches of non-corrosive, inert materials such as clean sand, earth or gravel, well-tamped in place; no clay or loam.
Tank(s) requires minimum 2 feet of earth cover or 1 foot of earth with a 4" reinforced concrete slab.
IN TRAFFIC AREAS:
1. Minimum 3 feet of earth cover or 18" of well-tamped earth plus 6" or
reinforced concrete or 8" of
asphaltic concrete.
2. When reinforced concrete or asphalt is used, it shall exceed at least 1 foot
horizontally beyond the outline of the
tank if all directions.
If in ground water, the tank shall be securely strapped to a concrete slab.
Tank and piping shall be protected by either:
1. a properly engineered, installed and maintained cathodic protection system in
accordance with recognized
standards of design, or
2. corrosion resistant materials of construction such as special alloys, fiber glass
reinforced plastic, or fiber
glass reinforced plastic coating or equivalent approved system.
Vent size shall be based on the tank capacity, but no less than 2" piping.
| Capacity of Tank (U.S. Gallons) | Approx. Imperial Gallons | Diameter of Vent (Iron Pipe Size) |
| 500 or less | 500 or less | 2 inches |
| 501 to 3,000 | 501 to 2,500 | 2 inches |
| 3,001 to 10,000 | 2,501 to 8,300 | 2 inches |
| 10,001 to 20,000 | 8,301 to 16,600 | 2 1/2 inches |
| 20,001 to 35,000 | 16,601 to 29,000 | 3 inches |
NOTE: Where tanks are filled by the use of a pump through tight connections, a vent pipe not less in size than the discharge of the pump should be used.
Vent and fill pipes shall be a minimum of 2 feet from any building opening.
Fuel lines shall have a protective cover over them to prevent damage if in any planting area.
Outside above-ground tanks less than 660 gallons shall meet the requirements of UL 80.
Tanks must be installed in a built-up area and protected from the weather and physical damage and shall not block paths of egress.
Tank and piping shall be tested at a minimum of 3 p.s.i. and a maximum of 5 p.s.i. air pressure unless manufacturer's recommendations are different. Test to be witnessed by the Fire Marshal's Office. Maximum gauge capacity not to exceed 30 p.s.i.
State Public Health Code requires tank to be a minimum of 75' from any well.
