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Issue Date: November 22, 1995
Revision Date: April 27, 2005
Purpora Engineering,
Inc.
(originally listed as Heath Consultants, Inc.)
Petro Comp
VOLUMETRIC TANK TIGHTNESS TEST
METHOD (OVERFILL)
| Certification |
Leak rate of 0.1
gph with PD = 99% and PFA = 0.98%. |
| Leak Threshold |
0.05 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, water. |
| Tank Capacity |
Maximum of 15,000
gallons.
Tank must be minimum 100% full.
An automatic product leveler must be used to maintain a constant product
level during test. |
| Waiting Time |
None between
delivery and testing.
There must be no dispensing or delivery during waiting time. |
| Test Period |
Minimum of 2
hours after the completion of the high level circulation.
Test data are acquired and recorded by system's computer after the
completion of the high level circulation.
Leak rate is calculated based on cumulative volume change during low level
test (generally based on 1 hour average volume change).
Product must be mixed continuously throughout test period.
There must be no dispensing or delivery during test. |
| Temperature |
Average for
product is determined by a single temperature sensor. |
| Groundwater |
Depth to
groundwater in tank excavation backfill must be determined.
If groundwater is above bottom of tank, product level must be adjusted to
provide a minimum net pressure of 4 psi at bottom of tank during test. |
| Calibration |
Temperature
sensor is self calibrating.
Level sensor must be checked annually and, if necessary, calibrated in
accordance with manufacturer's instructions. |
| Comments |
Not evaluated
using manifolded tank systems. |
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Purpora Engineering Inc.
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Evaluator:
Ken Wilcox Associates
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658 North Progress Drive
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Tel:
(816) 443-2494
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Saukville, WI 53080
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Date of
Evaluation: 12/15/90
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Tel: (262) 536-4081
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E-mail: info@purporaengineering.com |
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URL:
www.purporaengineering.com |
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