Sec. 11-18. Tanks, etc., for wholesale storage outside fire
limits.
Outside the fire limits, as now existing or as hereafter
changed or amended, no tanks of more than one hundred
thousand gallons capacity for the wholesale storage of gasoline,
benzine, naphtha or other flammable liquids shall be
erected or installed; provided, that nothing contained herein
shall prevent the repair or use of any such tank for this purpose
installed prior to the passage of the ordinance from which
this article is derived.
Tanks shall be of galvanized steel, of basis open hearth
steel or wrought iron, of a thickness according to the following
table:
Capacity
(gallons) |
Minimum thickness
(gauge—U. S. Standards) |
Lbs.
per sq. foot |
| 1 to 285 |
16 |
2.50 |
| 286 to 560 |
14 |
3.127 |
| 561 to 1100 |
12 |
4.375 |
| 1101 to 4000 |
7 |
7.50 |
| 4001 to 12000 |
¼″ |
10.00 |
| 12001 to 20000 |
5/16″ |
12.50 |
| 20001 to 30000 |
⅜″ |
15.00 |
Tanks above thirty thousand gallons capacity shall conform
to the National Board of Fire Underwriters standards.
Tanks shall be riveted, welded or brazed and shall be soldered,
caulked or otherwise made tight in mechanical and
workmanlike manner, and if to be used with a pressure discharge
system, shall safely sustain a hydrostatic test at least
double the pressure to which the tank may be subjected. The
top of the tank shall be securely fastened to the top ring with
joints of equal tightness to those between the rings. Tanks
shall be covered with asphaltum or other nonrusting paint or
coating. All pipe connections shall be made through flanges
or reinforced metal securely riveted, welded or bolted to the
tank and made thoroughly tight. The use of wooden-top tanks
is prohibited.
Tanks shall be constructed entirely of metal, including the
top, sides and bottom. All openings shall be gastight, except
beneath the vent, which shall be screened. All tanks shall be
electrically grounded by resting directly on moist earth or
otherwise electrically grounded to permanent moisture, preferably
to water piping, and to the satisfaction of the city
electrician and the chief of the fire department. No insulated
connection shall be permitted. Telephone or similar poles or
other projections liable to act as discharge points shall be
kept as far as practicable from tanks.
If buried underground, the tanks shall be lower than the
floors, basements, cellars or pits of all buildings within a
radius of fifty feet. The top of the tank shall also be at least
three feet under the ground and below any piping to which
the tank may be connected. Except in lieu of the three feet
of earth, tanks may be buried under eighteen inches of earth
and covered with reinforced concrete, at least six inches in
thickness, which shall extend at least one foot beyond the outline
of the tank in all directions, shall be set on a firm foundation
and shall be surrounded with soft earth or sand, well
tamped into place, or encased in concrete. The tank may
have a test well, if the test well extends near the bottom of
the tank and twelve feet above the source of supply, and the
top shall be hermetically sealed and locked, except when necessarily
open. The tank shall have a vent pipe at least one inch
in diameter which shall extend from the top of the tank to
at least twelve feet aboveground level, and shall terminate in
a goose neck protected in the outer end by a 40 × 40 mesh or
equivalent noncorrodible wire screen.
If erected aboveground, the tank shall conform to the same
specifications and requirements as heretofore outlined and, in
addition, such tank shall be erected only on steel or metal
supports of sufficient size and thickness for carrying the load
to be imposed thereon and on a concrete foundation.
All aboveground tanks shall be individually diked, or the
entire property, together with contiguous or adjoining property
used for such storage or piping, shall be provided with a
dike or retaining wall sufficient to prevent the discharge of
flammable liquids onto other property in case of a rupture in
the tanks or piping.
Such dikes or walls shall be of earth or masonry construction.
The impounding basin shall have a capacity of not less
than one and one-half times the capacity of the tank. The
height of the dike shall not exceed one quarter the height of
the tank but in no case be less than four feet high. The height
and capacity of the dikes shall be properly maintained to afford
the approved protection. Earthen dikes shall have a
flat section at the top and shall have a slope consistent with
the angle of repose of the materials of which they are constructed.
All installations under the authority of this article shall be
under the direction and meet with the approval of the city
manager, and all such installations shall be made in a workmanlike
manner and in accordance with recognized standards
consistent with safety and good engineering. Except when
herein otherwise provided, the applicable standards of the National
Board of Fire Underwriters shall be recognized. (Code
1959, § 11-18; 6-5-61; 12-18-67.)
