Certification
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Leak
rate of 0.2 gph with PD = 99.5% and PFA < 0.5%.
|
Leak
Threshold
|
0.1
gph for leak rate of 0.2 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. |
Tank
Capacity
|
Maximum
of 15,000 gallons.
Tank must be between 50 and 95% full. |
Waiting
Time
|
Minimum
of 4 hours between delivery and testing. |
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. |
Calibration
|
RTDs
and probe must be checked and, if necessary, calibrated
in accordance with manufacturer's instructions. |
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.
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.
|