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UST Inspector Training Webinar
Subtitle
Line Tightness Testing
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Line Tightness Testing
Tanknology TLD1 MethodConstant pressure line tightness testing
is used by many testing vendors. The principles of the test are
very similar from vendor to vendor. Tanknology’s TLD1 test method
will be used to illustrate the general principles of a “constant
pressure” line tightness test.
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Line Tightness Testing
Tanknology TLD1 Method
•Connect test apparatus to the product line
•Add like product until visible in the calibrated site glass
•Apply constant pressure using a bottled inert gas (usually
Nitrogen)
•Record site glass levels at uniform intervals
•Calculate leak rate
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Line Tightness Testing
The portion of the line to be The portion of the line to be
tested must be isolated from tested must be isolated from
dispensers, submersible dispensers, submersible pumps or other
associated pumps or other associated devices.devices.
••Check ValveCheck Valve
••Ball valveBall valve
••Isolation toolIsolation tool
Impact Impact ValvesValves
Calibrated Site GlassCalibrated Site Glass
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Line Tightness Testing
ExampleExample
IFIF
1.1. 1 increment = .005 gallons1 increment = .005 gallons
2.2. We measure a 5 increment change in 10 We measure a 5
increment change in 10 minutesminutes
THENTHEN
1.1. .005 x 5 = .025 Gallon loss .005 x 5 = .025 Gallon loss (10
minute loss)(10 minute loss)
2.2. .025 x 6 = .15 .025 x 6 = .15 GPHGPH loss loss (Projected
60 minute loss)(Projected 60 minute loss)
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Line Tightness Testing
• Level Drop may NOT equal a LeakDispenser Impact ValvesPacker
“O” RingCrack STP headAir / Vapor trapped in lineProduct
contraction
• Technician Training & Experience
• Proper Tools• Understanding Data Trends
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Line Tightness Testing
Field Technician Data FormField Technician Data Form
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Line Tightness Testing
Field Technician Data FormField Technician Data Form
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Line Tightness Testing
Pass / Fail thresholdsPass / Fail thresholds
CFR 40 280.44 Methods of release detection for piping
(b) Line tightness testing. A periodic test of piping may be
conducted only if it can detect a 0.1 gallon per hour leak rate at
one and one-half times the operating pressure.
Manufacturer Thresholds may Manufacturer Thresholds may be more
stringentbe more stringent
Steel +/Steel +/-- .01GPH.01GPH(10 x more stringent)(10 x more
stringent)
Fiberglass & Flexible +/Fiberglass & Flexible +/-- .02
GPH.02 GPH(5 x more stringent)(5 x more stringent)
Suction Systems +/Suction Systems +/-- .025 GPH.025 GPH(4 x more
stringent)(4 x more stringent)
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Line Tightness Testing
Test Data Interpretation
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LeakTight
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Line Tightness Testing
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Line Tightness Testing
