Certification
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Leak
rate of 0.2 gph with PD = 99.1% and PFA = 0.9% for Precision
Test.
Leak rate of 0.2 gph with PD = 95.4% and PFA = 4.6% for
Quick Test.
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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 15,000 gallons. Tanks less than 95% full may be tested.
Minimum product level required based on tank diameter
as follows:
48" dia/min 8.5";
64" dia/min 10.5";
72" dia/min 11.5";
96" dia/min 14";
126" dia/min 18".
For other tank diameters, see evaluation report.
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Waiting
Time
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Between
delivery and testing ranges from 1 to 6 hours depending
on tank conditions.
None between dispensing and testing.
There must be no delivery during waiting time.
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Test
Period
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Average
of 2 hours, 46 minutes during Precision Test evaluation.
Average of 1 hour, 9 minutes during Quick Test evaluation.
Test data are acquired and recorded by a microprocessor
which automatically determines test time based on tank
size and product level.
There must be no dispensing or delivery during test.
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Temperature
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Probe
contains 5 resistance temperature detectors (RTDs) to
monitor average product temperature.
At least one RTD 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 0.66 inches.
Minimum detectable change in water level is 0.039 inches.
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Calibration
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RTDs
and probe must be checked regularly 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.
Tests only the 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 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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