Issue Date: January 11, 2001
Revision Date: December 31, 2009
Estabrook EZY CHEK Systems
(originally listed as Horner EZY CHEK)
EZY 3 Locator Plus
NON-VOLUMETRIC TANK TIGHTNESS
TEST METHOD (VACUUM)
||Leak rate of 0.1
gph with PD = 100% and PFA = 1.6%.
||A tank system
should not be declared tight when the acoustic signal detected is
different from the baseline signal before a vacuum is placed on the tank,
or when water ingress is detected by the water sensor.
aviation fuel, fuel oil #4, waste oil.
||Maximum of 30,000
Ullage volume must exceed the greater of 1% of tank volume or 50
Maximum of 30,000 gallons per tank for manifolded tank systems with
microphone, water sensor and pressure monitoring gauges in each tank.
delivery and testing.
level in tank excavation backfill is below bottom of tank:
A few minutes to determine background noise and at least 2 minutes to run the
test after desired vacuum is reached.
When groundwater level in tank excavation backfill is above bottom of
tank or when the groundwater level in the tank excavation backfill has not
The time it takes for water ingress to increase the water level in the
tank to allow the water sensor to detect the "minimum detectable
change in water level" (see "Water Sensor" section below).
Test period based on water ingress is dependent on tank size. For example,
the test period is 36 minutes for a 10,000 gallon (96" dia x324" lg)
Before starting test, water sensor must be calibrated to "minimum
detectable water level" (see "Water Sensor" section below)
according to manufacturer's instructions.
There must be no dispensing or delivery during test.
differential across tank wall at bottom of tank must be at least 0.5
Pressure differential across tank wall is equal to the absolute value of
vacuum applied to tank, plus pressure of tank excavation backfill on tank,
plus groundwater pressure on tank, minus pressure of liquid in tank.
is independent of product temperature.
water sensor must be used to detect water ingress and must be calibrated for
every test when groundwater level in tank excavation backfill is above
bottom of tank or when the groundwater level in the tank excavation backfill
has not been determined.
Minimum detectable water level is 0.014 inch.
Minimum detectable change in water level is 0.0095 inch.
Minimum water level in tank must be adjusted to at least 0.014 inch
(sensor's minimum detectable water level) before calibrating sensor and
in tank excavation backfill must be determined by observation well or soil
probe in tank excavation backfill.
If groundwater level in tank excavation backfill is above bottom of tank or
the groundwater level in the tank excavation backfill has not been
determined, water sensor must be used and test time extended to ensure water
ingress detection during test.
||Microphone was 25
ft away from leak source during evaluation.
Although not tested on empty tanks, a third party acoustics specialist has
certified the device is equally effective when tanks are empty as when
tanks contain product.
Test may be inconclusive if there is high background noise.
Vacuum test method may not be effective in some tank excavation backfill
(such as clay) because it may plug holes in tank.
If free product is present in tank excavation backfill, a leak in the free
product zone may not be detected by a vacuum test method.
An observation well or soil probe in tank excavation backfill may help
determine backfill material, water level in tank excavation backfill, and
free product. Manufacturer must certify operator at least every 2
More than 4 psi pressure differential across the tank wall at any location
in the tank could damage tank.
EZY CHEK Systems
Ken Wilcox Associates