Issue
Date: June 1, 2001
Revision Date: October 18, 2002
OPW
Fuel Management Systems
(originally listed as Petro Vend, Inc.)
Site
Sentinel Models 1, II and III,
(Model 924, 2 inch dia Floats, Magnetostrictive Probe)
AUTOMATIC
TANK GAUGING METHOD
Certification
|
Leak
rate of 0.2 gph with PD = 97.8% and PFA = 2.2% for 30
minute test.
Leak rate of 0.2 gph with PD = 99.4% and PFA = 0.6% for
1 hour test.
Leak rate of 0.2 gph with PD = 99.7% and PFA = 0.3% for
2 hour test.
Leak rate of 0.2 gph with PD = 99.9% and PFA = 0.1% for
3 hour test.
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Leak
Threshold
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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.
Other liquids with known coefficients of expansion and
density may be tested after consultation with the manufacturer.
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Tank
Capacity
|
Maximum
of 20,000 gallons.
Tank must be minimum 50% full for 1 hour test.
Tank must be minimum 14% full for 30 minute, 2 hour and
3 hour test.
Minimum product level required based on 14% full tank
and tank diameter is as follows:
48" dia/min 9.5";
120" dia/min 24.7".
For other tank diameters, consult manufacturer.
|
Waiting
Time
|
Minimum
of 8 hours between delivery and testing.
There must be no delivery during waiting time.
Minimum of 30 minutes between dispensing and testing.
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Test
Period
|
Variable:
Minimum of 30 minutes, 1, 2 or 3 hours.
Test data are acquired and recorded by system's computer.
Leak rate is calculated as the difference between the
first and last data collected.
There must be no dispensing or delivery during test.
|
Temperature
|
Average
for product is determined by a probe containing 5 thermistors
with the lowest thermistor located at the 10% tank volume
level above the bottom of the tank.
|
Water
Sensor
|
Must
be used to detect water ingress.
Minimum detectable water level in the tank is 0.75 inch.
Minimum detectable change in water level is 0.08 inch.
|
Calibration
|
Thermistors
and probe must be checked and, if necessary, calibrated
in accordance with manufacturer's instructions.
|
Comments
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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.
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