NORA suggests the best way to properly size
a fuel storage tank is to estimate annual fuel
consumption then divide by 3.
Formula:1,800 ÷ 3 = 600
A 500 gallon tank or two 275 gallon
tanks will suffice.
Formula: 1000 ÷ 3 =333
A 275 or 330-gallon tank will suffice.
Formula: 750 ÷ 3 = 250
A tank no larger than 275 gallons
is recommended.
National Oilheat Research Alliance 9
Chapter 3
Storage Tank
Selection Criteria
Before installing a new or replacement tank
consider the factors that will affect the tanks
performance over its service life. These may
include:
1. What size should the tank be?
2. What regulations govern the installation?
3. Where will the tank be installed?
4. What factors will affect tank corrosion?
5. What type of tank is best suited for
the site?
After investigating each of these factors, discuss
your recommendations with the customer.
1. Tank Size
Tanks for permanent installation are available
in many shapes and sizes, from slightly
over 100 gallons to well over 1,000 gallons.
The 275-gallon AST is the most common tank
in residential use.
Historically, there have been no widely accepted
guidelines regarding selecting the tank
size for a particular building. The consensus is
the tank should be large enough to minimize
delivery frequency and small enough to ensure
the fuel doesn’t sit dormant for long periods.
The home heating industry is now frequently
relying on the use of above ground tanks as
the preferred method of storage. Underground
tanks are commonly being replaced with
smaller capacity above ground tanks. When a
larger tank storage system is needed, configurations
of multiple ASTs are used.
While smaller tanks do require more frequent
deliveries, their use is helpful in reducing the
Customer is expected to
use 1,800 gallons
Customer is expected to
use 1,000 gallons
Customer is expected to
use 750 gallons or less
time fuel resides in storage. Heating fuel is
susceptible to a natural aging process influenced
by heat, oxygen, microorganisms, metals
and oxides. When these influences combine
with moisture, either from condensation or
from water suspended in the fuel, an environment
for incubating tank sludge can be created.
This sludge can get in the piping, the filters,
the pumps, and the nozzle causing operational
problems. This is the primary reason regular
removal of accumulated water is recommended
throughout this guide.
Using the formula in the table above helps
assure the fuel in the tank is reasonably fresh
and resources are not challenged by excess
deliveries. Of course, there are unique situations
that may warrant changes, including
location of the tank and the customer’s preference
or concerns.
The key is to balance delivery frequency
with reasonable product turnover so aging of
fuel is minimized.