| Certification |
Leak rate of 0.2 gph with PD = 95.3% and
PFA = 4.7%. |
| Leak
Threshold |
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. |
| Applicability |
Gasoline, diesel, aviation fuel. |
| Tank
Capacity |
Maximum of 75,000 gallons.
Tank must be between 50 and 95% full. |
| Waiting
Time |
Minimum of 4 hours between delivery and
testing.
Minimum of 2 hours between dispensing and testing.
There must be no delivery during waiting time. |
| Test
Period |
Minimum of 24 hours.
Test data are acquired and recorded by system's computer.
Leak rate is calculated from the average of subsets of all data
collected.
There must be no dispensing or delivery during test. |
| Temperature |
Measurement of product temperature is not
required by this system. |
| Water
Sensor |
Must be used to detect water ingress.
Minimum detectable water level in the tank is 0.509 inch.
Minimum detectable change in water level is 0.225 inch. |
| Calibration |
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
system which routinely contains product. |
