Certification
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Leak
rate of 0.2 gph with PD = 98.9% and PFA = 1.1%.
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Leak
Threshold
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0.1
gph. A tank system should not be declared tight if the
test result indicates a loss or gain that equals or exceeds
this threshold.
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Applicability
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Gasoline,
diesel, aviation fuel, fuel oil #4. Other liquids with
known coefficients of expansion and density may be tested
after consultation with the manufacturer.
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Tank
Capacity
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Maximum
of 30,000 gallons. Tanks less than 95% full may be tested.
Minimum product level required is 10 inches.
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Waiting
Time
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Determined
automatically based on quality of tank data. Average during
evaluation was 8 hours, 56 minutes between delivery and
testing. Dispensing during waiting time may extend waiting
time. There must be no delivery during waiting time.
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Test
Period
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Determined
automatically based on quality of tank data. Average during
evaluation was 3 hours, 39 minutes. Test data are acquired
and recorded by a microprocessor. There must be no dispensing
or delivery during test.
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Temperature
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Average
for product is determined by probe containing 5 or more
IC (solid state) temperature sensors. At least one IC
temperature sensor must be submerged in product during
test.
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Water
Sensor
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Must
be used to detect water ingress. Minimum detectable water
level in the tank is 0.5 inch. Minimum detectable change
in water level is 0.03 inch.
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Calibration
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IC
(solid state) temperature sensors and probe must be checked
and, if necessary, calibrated in accordance with manufacturer's
instructions.
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Comments
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Not
evaluated using manifolded tank systems. Therefore,
this certification is only applicable when there is
a probe used in each tank and the siphon is broken during
testing.
Evaluated in automatic mode where a test is run whenever
conditions in tank are quiet for a sufficient amount
of time.
If test is run manually, vendor recommends waiting at
least 7 hours after delivery and allowing the automatic
tank gauge to determine minimum test period to avoid
inconclusive results. Not evaluated using manifolded
tank systems.
Tests only portion of tank containing product. As product
level is lowered, leak rate in a leaking tank decreases
(due to lower head pressure). Consistent testing at
low levels could allow a leak to remain undetected.
EPA leak detection regulations require testing of the
portion of the tank system which routinely contains
product.
California regulations
require at least one test per month after routine product
delivery or when the tank is filled to within 10% of
the highest operating level of previous month.
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