A 1-inch (25 mm) antifreeze-type, lockable,
water drawoff valve with internal poppet at
the low end of the tank, unless tank contains
aviation turbine fuels with icing hibitors.
In those cases, the water drawoff valve may be
Water drawoff connections. See Plate No. 017.
A 1-inch (25 mm) connection from the low end
of the tank to approximately 3.5 feet (1.1 m)
above the ground and equipped with a positive
displacement-type, hand-operated pump for
water drawoff. For Air Force projects, use
electrical pumps only.
A water removal suction tube at low end of
tank with connection for water removal by
truck. Consider installing a fixed, hand-
operated pump as an alternative.
A central sump pump.
Ball joints on pipes to relieve strain caused
by tank settling or seismic activity. Ensure
that contract specifications do not allow
piping connections to be made until after the
tank has been completely tested and allowed to
settle. As an alternative, settlement
calculations can be made and piping
flexibility can be designed to account for
settling. In this case, pipe can be connected
prior to testing.
* May be required on tanks 25,000 gallons (94
600 L) and larger.
Vertical Aboveground Storage Tank
Horizontal Aboveground Storage Tank
Horizontal Underground Storage Tank
Aboveground Concrete-Encased Storage Tank
Vertical Underground Storage Tank