(2) Activate the "Overfill Fuel Level" alarm at 95% of the rated
tank capacity.
2.3.4.4
Arrangement
Integral tanks may allow gravity flow into the engine. Gravity flow tanks
and any tank that allows a fuel level above the fuel injectors shall be
provided with an internal or external factory installed valve located as
near as possible to the shell of the tank. The valve shall close when the
engine is not operating. Integral day tanks shall be provided with any
necessary pumps to supply fuel to the engine as recommended by the
generator set manufacturer. The fuel supply line from the tank to the
manufacturer's standard engine connection shall be welded pipe.
2.3.5
Day Tank
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NOTE: Delete this paragraph if an integral main
fuel storage tank is used.
See NFPA 37 restrictions on allowable day tank sizes
and enclosures. Select either self-supporting or
integral day tank. Select the first option below
for applications where fuel is returned to the day
tank. Select the second option below for
applications where fuel is returned to the main
tank. Integral day tanks allow for 1 to 8 hours of
operation. Consult generator set manufacturer for
integral day tanks. Standby applications for use
with fire pumps will have day tanks sized for 8
hours duration. Select day tank capacity for either
prime or standby application. The day tank can be
sized by the designer or the contractor. The size
of the day tank should be based on a fuel flow rate
that is equal to the value of a typical engine
manufacturer for the indicated engine generator
size. A value of 200% of the expected fuel
consumption of the engine is not unusual for the
flow rate of the main fuel pump. The excess fuel
may be returned to the day tank or main fuel tank.
The designer should also consider the impact of heat
build up when sizing the day tank. If a fuel oil
cooler is not used or if fuel is returned to the day
tank, the day tank size may need to be increased to
properly dissipate the heat absorbed by the fuel.
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Each engine shall be provided with [a separate self-supporting][integral]
day tank. [Each day tank shall be provided with connections for fuel
supply line, fuel return line, fuel overflow line, local fuel fill port,
gauge, vent line, drain line, and float switch assembly for control. A
fuel return line cooler shall be provided as recommended by the
manufacturer and assembler. The temperature of the fuel returning to the
day tank shall be below the flash point of the fuel. A temperature sensing
device shall be installed in the fuel supply line.] [Each day tank shall
be provided with connections for fuel supply line, fuel overflow line,
local fuel fill port, gauge, vent line, drain line, and float switch
SECTION 16264A
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