| Certification |
Leak rate of 0.2
gph with PD = 99.9% and PFA = 0.1% for Precision Test.
Leak rate of 0.2 gph with PD = 97.0% and PFA = 0.1% for Quick Test.
Leak rate of 0.1 gph with PD = 95.2% and PFA = 0.8% for 0.1 gph Test |
| Leak
Threshold |
0.1 gph for leak
rate of 0.2 gph, Precision Test.
0.128 gph for leak rate of 0.2 gph, Quick Test.
0.06 gph for leak rate of 0.1 gph, 0.1 gph Test.
A tank system should not be declared tight if the test result indicates a
loss that equals or exceeds this threshold. |
| Applicability |
Gasoline, diesel,
aviation fuel, fuel oil #4. |
| Tank
Capacity |
Maximum of 20,000
gallons.
Tanks less than 95% full may be tested.
Minimum product level required based on tank diameter is as follows:
48" dia/ min 18";
64" dia/ min 21";
72" dia/ min 24";
96" dia/ min 30";
126" dia/ min 39".
Minimum product level required for other tank diameters; multiply probe
length by 0.08 and add 5 inches. |
| Waiting
Time |
Minimum of 1 hour
between delivery and testing for Quick Test.
Minimum of 6 hours between delivery and testing for Precision Test and 0.1
gph Test.
There must be no delivery during waiting time. |
| Test
Period |
Minimum of 2
hours for all tests.
Test data are acquired and recorded by system's computer.
Leak rate is calculated from data determined to be statistically
valid.
There must be no dispensing or delivery during test. |
| Temperature |
Average for
product is determined by a probe with 5 thermistors.
The bottom thermistor must be submerged in at least 5 inches of product
during test. |
| Water
Sensor |
Must be used to
detect water ingress.
Minimum detectable water level in the tank is 0.878 inch.
Minimum detectable water level change is 0.013 inch.
System is default programmed to report a water depth only when it exceeds
3.5 inches.
System can be programmed to report a water depth of 0.878 inch and above. |
| Calibration |
System 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. |
