Issue
Date: November 14, 1997
Revision Date: January 11, 2001
Andover
Controls Corp.
Andover
Infinity Versions CX9900, CX9400, CX9200, CX9000, CMX240
(Magnetostrictive Probe)
AUTOMATIC
TANK GAUGING METHOD
Certification
|
Leak
rate of 0.2 gph with PD = 95.4% and PFA = 4.6%.
|
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 with known coefficients of expansion and
density may be tested after consultation with the manufacturer.
|
Tank
Capacity
|
Maximum
of 30,000 gallons.
Tank must be between 50 and 95% full.
|
Waiting
Time
|
Minimum
of 6 hours between delivery and testing.
Minimum of 3 hours between dispensing and testing.
There must be no delivery during waiting time.
|
Test
Period
|
Minimum
of 6 hours.
Test data are acquired and recorded by system's computer.
Leak rate is calculated as the average of subsets of all
data collected.
There must be no dispensing or delivery during test.
|
Temperature
|
Average
for product is determined by a minimum of 3 resistance
temperature detectors (RTDs).
|
Water
Sensor
|
Must
be used to detect water ingress.
Minimum detectable water level in the tank is 0.35 inch.
Minimum detectable change in water level is 0.0028 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 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.
|