Issue Date: November 22,
1995
Revision Date: November 14, 1997
Egemin
Naamloze Vennootschap
E'sPI
IV (Mass Buoyancy Probe)
AUTOMATIC
TANK GAUGING METHOD
Certification
|
Leak
rate of 0.2 gph with PD = 97.2% and PFA = 0.3%.
|
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 15,000 gallons. Tank must be between 50 and 95% full.
|
Waiting
Time
|
Minimum
of 6 hours between delivery and testing. There must be
no dispensing or delivery during waiting time.
|
Test
Period
|
Minimum
of 2 hours, 15 minutes. Test data are acquired and recorded
by system's computer. Leak rate is calculated from average
of subsets of all collected data. There must be no dispensing
or delivery during test.
|
Temperature
|
Average
for product is determined by a minimum of 5 thermistors.
|
Water
Sensor
|
Must
be used to detect water ingress. Minimum detectable water
level in the tank is 0.253 inch. Minimum detectable change
in water level is 0.029 inch.
|
Calibration
|
Thermistors
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.
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