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Issue Date: August 23, 1999
Revision Date: March 31, 2006
Vista Precision Solutions, Inc.
(originally listed as Vista Research, Inc.)
Model HT-100-n
Monitoring Method and Line Tightness Test Method Version 1.0, Version 1.1
Line Leak Detection Method for Airport Hydrant and Field Constructed Systems
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Certification |
Leak rate of
0.004%÷ √¯(n) of line capacity (for n=4, 0.02 gph per 1000 gallons of
product) with PD = 95% and PFA = 1.25% for
Version 1.0, where n is the number of tests averaged together (smallest leak
rate for Version 1.0 evaluation, which was conducted on a 306,477 gallon
line at 160 psi where n = 3, was 7.08 gph).
Leak rate of 0.00209%÷ √¯(n) of line capacity (for n=4, 0.01045 gph
per 1000 gallons of product) with PD = 95% and PFA =
5% for Version 1.1, where n is the number of tests averaged together
(smallest leak rate for Version 1.1 evaluation, which was conducted on a
306,477 gallon line at 160 psi where n = 3, was 3.71 gph).
The USEPA has not set a minimum detectable leak rate for large diameter
pipeline systems (airport hydrant systems) at the time of this evaluation. |
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Leak Threshold |
0.00282% ÷ √¯(n)
of line volume in gph for Version 1.0. 0.000916% ÷ √¯(n) of line volume in
gph for Version 1.1.
A pipeline system should not be declared tight if the test result indicates
a loss that equals or exceeds these thresholds. |
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Applicability |
Gasoline, diesel,
aviation fuel, fuel oil #4.
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Specification |
System tests
fiberglass or steel piping.
Tests are conducted at operating pressure to a maximum of 200 psi.
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Pipeline Capacity |
Maximum of
612,954 gallons.
Minimum of 3,000 gallons. |
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Waiting Time |
None between
delivery and testing.
None between dispensing and testing. |
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Test Period |
Minimum of 3
hours, 10 minutes after setup and after pipeline is fully isolated.
Test data are acquired and recorded by a microprocessor.
Calculations are automatically performed by the microprocessor.
Averaging of individual tests, where tests may be selected over any time
frame yet not necessarily consecutive. |
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System Features |
System may be
permanently installed on pipeline to perform monitoring, or may be
transported and set up to perform line tightness testing.
A single 3-hour 10-minute test is required consisting of a 1-hour 10-minute
monitoring period at operating pressure, and a 2-hour monitoring period at
atmospheric pressure.
System measures change in volume and reports output quantity in gph, while
compensating for thermal effects. Printed message and alarm activation if
leak is declared. |
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Calibration |
System must be
calibrated in accordance with manufacturer’s instructions.
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Comments |
System is to be
used only on large bulk pipelines and airport hydrant fueling systems.
This evaluation utilized a total of 87 tests, one with an induced leak rate
of 13.1 gph. |
Vista Precision Solutions, Inc. |
Evaluator: Ken Wilcox
Associates |
2350 Lindberg Loop |
Tel: (816) 443-2494 |
Richland, WA 99354 |
Date of Evaluation:
11/24/98 |
Tel: (509) 943-2484 |
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