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Certification
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Leak rate of 0.1 gph with PD = 99% and PFA = 1% for Precision
Test.
Leak rate of 0.1 gph with PD = 96% and PFA = 4% for Quick Test.
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Leak Threshold
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0.05 gph.
A tank system should not be declared tight if the
test result indicates a loss or gain which 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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Minimum of 6 hours between delivery and testing.
None between
dispensing and testing.
There must be no delivery during waiting time.
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Test Period
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Minimum of 3 hours, 45 minutes for Precision Test.
Average of 3
hours 45 minutes at 95% full and 5 hours 58 minutes at 50% full during Precision
Test evaluation. Minimum of 1 hour, 49 minutes for Quick Test.
Average of 1 hour
48 minutes at 95% full and 2 hours 48 minutes at 50% full 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 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.
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