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Issue Date: December 5, 2002
Engineering Design
Group, Inc.
Ronan X-76 CTM
Automatic Tank Gauging System
(MTS Level Plus UST Probe)
BULK UNDERGROUND STORAGE TANK
LEAK DETECTION METHOD (50,000 gallons or greater)
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Certification |
Leak rate is proportional to product
surface area (PSA).
For tanks with PSA of 564 ft², leak rate is 0.2 gph with PD > 99.9% and PFA
< 0.1%.
For other tank sizes, leak rate equals [(PSA in ft² ÷ 564 ft²) x 0.2 gph].
Example: For a tank with PSA = 846 ft²; leak rate = [(846 ft² ÷ 564 ft²) x
0.2 gph] = 0.3 gph.
Leak rate may not be scaled below 0.2 gph. |
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Leak Threshold |
Leak threshold is proportional to product
surface area (PSA).
For tanks with PSA of 564 ft², leak threshold is 0.1 gph.
For other tank sizes, leak threshold equals [(PSA in ft² ÷ 564 ft²) x 0.96
gph].
Example: For a tank with PSA = 846 ft²; leak threshold = [(846 ft² ÷ 564
ft²) x 0.1 gph] = 0.15 gph.
Leak threshold may not be scaled below 0.1 gph.
A tank system should not be declared tight if the test result indicates
a loss or gain that equals or exceeds the calculated leak threshold.
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Applicability |
Gasoline, diesel, aviation fuel, fuel oil
#4.
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Tank Capacity |
Use limited to single, field-constructed,
vertical-walled tanks having a capacity of 50,000 to 75,000 gallons.
Maximum product surface area (PSA) is 846 ft². |
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Waiting Time |
Minimum of 4 hours, 48 minutes after
delivery or transfer. |
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Test Period |
Minimum of 6 hours. There must be no
delivery, transfer, or dispensing during test. |
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Temperature |
Average for product is determined by five
resistance temperature detectors (RTDs). |
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Water Sensor |
Must be used to detect water ingress.
Minimum detectable water level in the tank is 0.874 inch.
Minimum detectable change in water level is 0.011 inch.
For tanks with a product surface area (PSA) of 564 ft² and containing 0.874
inches of water, system takes more than 64 days to detect a 0.20 gph water
ingress rate. |
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Calibration |
System must be checked and, if necessary,
calibrated in accordance with manufacturer's instructions.
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Comments |
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.
Evaluated in nominal 50,000 gallon tank with PSA of 564 ft². |
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Engineering Design Group, Inc. |
Evaluator: Ken Wilcox Associates |
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Manufacturer’s Previously Listed Contact Information is No
Longer Valid. |
Tel:
(816) 443-2494 |
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Date of
Evaluation: 11/16/01 |
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