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Line Tightness and Leak Detector Testing
Petro-Tite Line Tightness TesterJuly 15, 2015
Chattanooga, Tennessee
Line Tightness Test RequirementsTennessee UST Regulations
•Must detect 0.1 GPH release at 1 ½ times operating pressure
•Required by rule at installation; Rule 400-18-01-.02(1)(d)6.
•Results must be maintained until next test; Rule 400-18-01-.04(5)(b)
•Required annually for pressurized piping; Rule 400-18-01-.04(2)(b)1.
– Unless site is using monthly monitoring (interstitial monitoring, SIR, electronic LLD)
Terminology- Pressurized Piping
• Full Pump Pressure• LLD Holding Pressure• LLD Metering Pressure• LLD Opening Time• Maximum Allowable Bleedback• Leak Rate in Gallons per Hour
Submersible Pump
Terminology- Continued
Shear Valve
• Safety Device
• Test port• Properly
Anchored
Petro-Tite Line Tightness Tester
Petro-Tite Line Tightness Tester
High Pressure Gauge
0-160 PSI
Rarely needs to exceed 75 PSI for petroleum applications
Petro-Tite Line Tightness Tester
Volumetric Burette
Graduated in mL and gallons
0.1 gallon capacity
DO NOT OVERFILL
Purpora Engineering
“Silver Bullet”Hoke Valve- controls flow ON/OFF
Needle Valve- fine adjustTest AdaptorAir EliminatorHydraulic Hose
Other Testing Systems
Estabrook EZ CHEK
•Uses nitrogen gas•Can test multiple lines
Acurite Line Tester
Tanknology TLD-1Tanknology TLD-1
Used only by Tanknology technicians
Uses Nitrogen gas
Preparing to Test Site Safety Meeting Deactivate sub pump (SAFETY
FIRST) Connect to line- shear valve at
furthest dispenser No ball valve- use “silver bullet”
Site Safety
STP relay stuck in ON position
ALWAYS DEACTIVATE STP at the electrical panel !
Site Safety cont.• STP Sumps >4 feet deep (ingress)• Gasoline Vapors- flammable AND
TOXIC• Displaced oxygen• Motor Vehicles/Pedestrians• Cones/Barricades• PPE- Gloves, vest, glasses, boots• Partner always recommended
Preparing to Test• REMOVE LEAK DETECTOR and
connect at the STP when :– No in-line ball valve present at STP– Confirming STP leaking into tank (o-
rings, check valve or functional element)– Testing large or long flex lines – Bad fittings at shear valve
Common Line Testing Problems
• Bad Functional Element- leaks into tank• NO BALL VALVE- must test at the tank.• Satellite Dispensers• Air/Vapor Pockets• Piping Deflection (flex pipe)• Liquid/Vapors in STP sump
Example 1- Temperature Change
o Large Pressure Changeso Small Volume Changeso Diminishes to “0” PSI
o SOLUTION- obtain 2-3 readings w/no change; can be prevented by purging line prior to test.
Time (Military)
Event Description Pressure (psi) Volume (gallons)Comments/Actions
(List leaks observed even if repairs are made and retest passes) Before After Before After Net Change
0800 Begin Line Test 50 0815 21 50 .0850 .0810 -.0040 0830 30 50 .0810 .0780 -.0030 0845 37 50 .0780 .0755 -.0025 0900 42 50 .0755 .0735 -.0020 0915 45 50 .0735 .0720 -.0015 0930 47 50 .0720 .0710 -.0010 0945 49 50 .0710 .0705 -.0005 1000 50 50 .0705 .0705 .0000
Example 2- Pipe DeflectionTime
(Military)Event Description Pressure (psi) Volume (gallons)
Comments/Actions
(List leaks observed even if repairs are made and retest passes) Before After Before After Net Change
0940 Begin Line Test 50 0950 43 50 .0655 .0610 -.0045 1000 46 50 .0610 .0570 -.0040 1010 48 50 .0570 .0535 -.0035 1020 49 50 .0535 .0515 -.0020 1030 49.5 50 .0515 .0500 -.0015 1040 49.8 50 .0500 .0490 -.0010 1050 49.9 50 .0490 .0485 -.0005 1100 50 50 .0485 .0485 .0000
o Small Pressure Losseso Small Volume Losseso Diminishes to “0” PSIo Gradual volume changes; 30 minutes-1 hours
o Solution: Conduct Beginning Bleedback Test and stretch line prior to test
Example 3- Air/Vapor PocketTime
(Military)Event Description Pressure (psi) Volume (gallons)
Comments/Actions
(List leaks observed even if repairs are made and retest passes) Before After Before After Net Change
1400 Begin Line Test 50 1405 46 50 .0910 .0260 -.0065 Re-filled burette1410 45 50 .0860 .0410 -.0041 Re-filled burette1415 46.5 50 .0770 .0070 -.0070 Re-filled burette1420 46.0 50 .0850 .0300 -.055 Re-filled burette
o Small Pressure Changeso Very Large Volume Changeso Non-repeating and inconsistent
SOLUTION: End test and purge air from line; locate any potential points of air (siphon lines, low points in product line, dead ends)
Example 4- High Rate of Leak
Time (Military)
Event Description Pressure (psi) Volume (gallons)Comments/Actions
(List leaks observed even if repairs are made and retest passes) Before After Before After Net Change
1315 Begin Line Test 50 1320 15 50 .0750 .0200 -.0045 Re-filled burette1325 17 50 .0830 .0260 -.0040 Re-filled burette1330 14 50 .0910 .0330 -.0035 Re-filled burette1335 16 50 .0780 .0220 -.0020 Re-filled burette1340 15 50 .0870 .0320 -.0015 Re-filled burette
o Large Pressure Losseso Large Volume Losseso Repeated and Consistent Losses over timeo May have to speed up readings, rapid pressure
changes for large leaks
Testing Mechanical Leak Detectors
Mechanical Line Leak Detectors (MLLD)
Invented in 1958 by Elmer Deter, Red Jacket Application Engineer
Alerts operator of nozzle to lowline pressure
MLLD Operation
Electronic Line Leak Detectors (ELLD)
• Tests line during idle time• Must simulate a 3.0 GPH leak to test• Programming must be verified
– Pressure based (Veeder-Root PLLD)– Flow based (Franklin/OPW)
ELLD Testing • Activates STP
during idle to conduct testing
• Secondary containment may be required
ELLD Operability
Simulating a Leak
Petro-Tite LLD Test1) Connect pressure regulator2) Energize STP, adjust pressure to 10 PSI3) Adjust Petro-Tite flow rate to 189 ml/min (3 gallons per hour)- black hoke valve4) De-energize STP5) Remove regulator and connect piping to Petro-Tite system
Petro-Tite LLD Test
5) Reactivate STP; MLLD should stay in leak test mode (1 gal/minute)
6) Keep STP running and close 3-way valve; MLLD should close, full flow.
QUESTIONS?
Don TaylorEnvironmental Consultant
TDEC- Division of Underground Storage Tanks(423) 854-5391
Don.Taylor@tn.gov