General
The information contained herein is in
no way intended to address all safety concerns and/or code requirements
associated with the installation or use of abovegroundtanks or associated
equipment. This information is provided solely as a guide to the end user
during the planning process for an Areo Power installation and will require
adjustment as necessitated by local codes and authorities. Areo Power Unitized
Fueler, Inc. recommends utilizing the services of a Professional Engineer
familiar with national, provincial and local codes to define all requirements
and obtain necessary permits prior to installation.
Setbacks
Depending on the characteristics of the fluid being stored,
it is necessary to locate aboveground at some minimum distance to property
lines, buildings, public ways, etc. and between adjacent tanks. Generally
accepted setback distances for tanks storing flammable or combustible are
outlined in NFPA 30.
Venting
All Areo Power tanks are supplied with an emergency venting
device to relieve tank pressure in the case of over pressurization. The
total emergency venting capacity required for the Areo tank is the sum of
the emergency and normal vent capacities. It is therefore very important
that the installer use a normal vent pipe size equal to the nominal diameter
of the vent fitting indicated on the tank drawing. The normal vent pipe
should terminate at least 12' above grade or 4' above the tank surface,
whichever is greater. Vent pipes should also be 5' from any building opening
and not located so that vapors may be trapped under eaves or other obstructions.
Vent caps should be designed to direct vapors up or horizontally away from
the tank or any adjacent obstructions.
Concrete Pad Foundation
It is recommended that a concrete pad foundation
be used for all Areo-Power aboveground tanks. A typical specification is
8 inch thick concrete reinforced with 6"x 6", #10 x #10 WWM. The concrete
should have a compressive strength of 3500 psi at 28 days. Pad dimensions
should be at least 12 inches larger than the tank footprint dimensions all
around. In flood plain areas, it is recommended that the tank and dike be
secured to the concrete pad to prevent float-off.
Tank Barriers
Depending on the location, it may be necessary
to protect the tank and associated equipment from vehicular impact. Bollards,
"jersey barriers" or highway guardrail is commonly used for this purpose.
Bollards are normally specified as 6" schedule 40 pipe 4' above ground,
2' under, filled with concrete and anchor in 2' diameter, 2' deep concrete.
Maximum spacing between barriers is usually 5' and the distance from thetank
is usually between 3' and 5'.
Dispensing
Areo Power recommends using suction pumps for dispensing
whenever possible. An anti-syphon valve should always be used with suction
pumps and should always be at the highest point in the suction piping system
(usually at the tank fitting). When this type of system is used the dispenser
can be located on the tank or on the pump platform. If a pressurized system
is being used (submersible pump) appropriate impact, check and normally
closed solenoid valve should be used along with underground piping and concrete
dispenser island. Areo Power recommends the use of a "breakaway coupling"
on hoses for all dispensing applications.
Filling
Filling is normally done at the fill containment
chamber at the top of the staircase. A drop tube (fill pipe) is recommend
and should terminate within 6" of the tank bottom. Some jurisdictions may
require a gauge, vent whistle, high level alarm and/or fill limiting device
be installed in aboveground tanks. These items are available through Areo-Power
and can be shipped loose with the tank.
Leak Monitoring
The design of the Areo Power tank allows for visible
monitoring of the containment dike. Some jurisdictions, however require
the use of electronic leak monitoring systems. These items are also available
through Areo-Power and can be shipped loose with the tank.
Electrical
Flammable and Combustible liquid tanks require hazardous location electrical work. All electrical equipment for use in this area should be listed for hazardous locations use. Equipment not rated for hazardous locations must be located outside of the hazardous zones described in NFPA 30A, the National Electrical Code and by the authority having jurisdiction. An emergency electrical disconnect marked "EMERGENCY SHUTOFF SWITCH" should also be mounted in a location visible from the dispenser. Electrical grounding may be required in some locations. Areo Power tanks can be supplied with grounding lugs to aid in fulfilling this requirement.