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Certification |
Leak rate of 0.2 gph with PD = 99.5% and PFA < 0.5%.
Leak rate of 0.1 gph with PD = 96.9% and PFA = 3.1%. |
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Leak Threshold |
0.1 gph for leak rate of 0.2 gph.
0.05 gph for leak rate of 0.1 gph.
A tank system should not be declared tight if the test result indicates a
loss or gain which equals or exceeds the applicable threshold. |
|
Applicability |
Gasoline, diesel, aviation fuel, fuel oil #4.
Other liquids with known coefficient of expansion and density may be tested
after consultation with the manufacturer. |
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Tank Capacity |
Maximum of 15,000 gallons.
Tank must be between 50 and 95% full. |
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Waiting Time |
Minimum of 4 hours between delivery and testing. |
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Test Period |
Minimum of 5 hours.
Test data are acquired by and recorded by system’s computer.
There must be no dispensing or delivery during test. |
|
Temperature |
Average for product is determined by a minimum of 5
resistance temperature detectors (RTD’s).
Sensors located above the liquid level are electronically removed from the
data analysis. |
|
Water Sensor |
Must be used to detect water ingress.
Minimum detectable water level in the tank is 1.1 inches.
Minimum detectable water level change is 0.015 inch. |
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Calibration |
RTDs and probe must be checked and, if
necessary, calibrated in accordance with manufacturer’s instructions. |
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Comments |
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 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. |
