Vent pipe — The vent pipe must be piped
from the vent alarm to the outside of the building.
Install swing joints to maintain the proper pitch.
Install a 90-degree elbow on the pipe outside the
building and connect a nipple into the elbow to
extend the vent pipe at least 6" above the level
of the fill pipe cap. Position the vent pipe so that
it’s close to the building and close enough to the
fill pipe for the vent alarm to be clearly heard
during delivery. Terminate the vent pipe in an approved
cap at least 2' from any building openings
and 5' from any appliance air inlets or flue gas
outlets.
Tappings — Install plugs in any unused top
tappings. If the tank has a NPT opening on the
bottom and the fuel lines are installed through the
top of the tank, it’s best to install a valve so that
any accumulated water can be easily removed.
The valve should be left closed with the handle
removed AND plugged to reduce the possibility
of fuel draining from the tank inadvertently.
20 National Oilheat Research Alliance
Burner supply — Install a fusible link
safety shutoff valve into the ½" threaded bung
on the bottom of the tank. Install the filter after
the shutoff and connect to the burner with a
new coated copper tubing or a steel pipe supply
line.
Outdoor Above Ground Tank
Installation Considerations
• Outside ASTs must be installed on a
rigid, non-combustible base. Generally,
6" of reinforced concrete is acceptable.
In some areas prefabricated concrete
slabs are also permissible. The tank
should be attached to the base
• Outside above ground tanks require
a vent alarm
• Tanks should not be located in places
where they may be subject to damage
Any valve installed in the bottom of an outdoor tank should be of a type that will not crack or break if it has filled
with water and then freezes.