||Leak rate of 0.1
gph with PD = 99.5% and PFA = 0.5%.
A tank system should not be declared tight if the test result indicates a
loss or gain that equals or exceeds this threshold.
aviation fuel, fuel oil #4.
||Maximum of 18,000
Tank must be between 92 and 100% full.
||Minimum of 12
hours between delivery and testing.
Minimum of 3 hours between "topping off" and testing.
There must be no product dispensing or delivery during waiting time.
||Minimum of 1
Test data are acquired and recorded by system's computer. Leak rate is
calculated from data determined valid by statistical analysis.
There must be no dispensing or delivery during test.
product is determined by a minimum of 6 temperature sensors.
groundwater in tank excavation backfill must be determined.
If groundwater is above bottom of tank, product level must be adjusted to
provide net pressure of 2-4 psi on bottom of tank during test.
must be calibrated in accordance with manufacturer's instructions before
each test. Temperature sensors must be calibrated in accordance with
manufacturer's instructions semi-annually.
using manifolded tank systems.
Tests only portion of tank containing product.