Certification
|
Leak rate of 0.2 gph with PD = 95.0% and PFA = 5.0%.
|
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, fuel oil #4.
Other liquids may be tested after consultation with
the manufacturer.
|
Tank Capacity
|
Maximum of 20,000 gallons.
Minimum product level required is 25% of the tank diameter.
|
Waiting Time
|
Minimum of 2 hours between delivery and testing.
There must be no delivery during waiting time.
|
Test Period
|
Minimum of 20 hours.
There must be no dispensing or delivery during test.
|
Temperature
|
Average for product is determined by a temperature-averaging
probe.
Temperature is measured by a resistance temperature
detector (RTD).
The RTD is mounted in a metal pipe that runs the length*
of the probe allowing for temperature averaging.
(*starts about 1 inch above the tip of the probe)
|
Water Sensor
|
Must be used to detect water ingress.
Minimum detectable water level in the tank is 1.298
inch.
Minimum detectable change in water level is 0.046 inch.
|
Calibration
|
The probe
features 10 measurement segments (10 capacitance segments)
and uses a comparison method (self calibration process)
which allows the sensor to run without any external
calibration. |
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.
System consists of a capacitance probe, a micro processing
unit inside the head of the probe, and a separate control
panel to record and display test data.
Probe was not tested with oxygenated fuels. However,
manufacturer states that probe will work with these
types of blended products.
Probe is based on the capacitive comparison method.
Product Level measurements taken by probe are not affected
by liquid properties such as density or dielectric constant,
electrical resistance, or surface turbulence.
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.
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.
|