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Operation of VMI LDT-890(\AF) Leak Detector Tester for
Catastrophic Leak Test
Successful
completion of this test establishes qualification for certification by
VMI to generate catastrophic (3 GPH @ 10 PSI) leaks for the post
installation testing, annual testing and trouble shooting of mechanical
(MLLD) and electronic line leak detection (ELLD). This test is specific
to VMI MLLD and ELLD and is also applicable to any mechanical or
electronic line leak detection system insofar as manufacturer guidelines
due not exclude this method of generating catastrophic
leak testing.
Specific instructions as to when and how to introduce a leak and the
specific instructions of when and how to determine failure are directed
by: 1) Federal Rules and Regulations 2) State Rules and Regulations 3)
Manufacturer Guidelines. Refer to “Install and Replace VMI Mechanical
Line Leak Detectors” for installation and replacement certification of
VMI MLLD’s.
Circle the correct
answer
1. VMI 99 series 2” leak detectors being used on a 30 psi
pump will go to leak search at
A. approximately 18 psi
B. approximately 30 psi
C. approximately 21 psi
2. All VMI 99 series leak detectors search for leaks at a
higher pressure than other manufacturer’s
MLLD’s.
True
False
3. VMI 99 series 2” leak detectors being used on a 24 PSI
pump will go to leak search at
A. approximately 18 psi
B. approximately 30 psi
C. approximately 21 psi
4. There are two gauges on the LDT-890(\AF) leak detector
tester. Which gauge would you look at to
determine if the
leak detector has found and is holding the leak?
A. Right hand gauge
B. Left hand gauge
5. Using the LDT-890(\AF) leak detector tester, you are testing
a 99 LD-3000 leak detector that
is installed on a 5 hp pump
and the right hand gauge is reading 40 psi. In what position is the leak
detector?
A. Full flow
B. Reset
C. Leak search
6. When using the LDT-890(\AF) you must first purge the piping
system and the LDT-890(\AF) of air.
True
False
7. To calibrate the LDT-890(\AF) to find a 3 gallon per hour
leak, you should turn the 4-way valve to
A. Dispenser Nozzle Position
B. GPH Test
C. Calibrate G.P.H.
D. Pressure Step Test
8. On an LDT-890(\AF)
Leak Detector Tester
the Calibrate Orifice knob is used to adjust the leak
search pressure.
True
False
9. If the pump is
off and the line pressure is reading zero psi, what position is the leak
detector in?
A. Leak Search
B. Reset/Park
C. Full Flow
10. A mechanical line leak detector cannot function on above
ground storage tanks with underground
piping.
True
False
11. Resiliency (bulk modulus) of a product line is measured by
bleed-back. Bleed-back is measured by;
A. With a beaker held under LDT-890(\AF),
turn on pump, watch the right hand gauge go to full
pressure, turn
off pump, set 4-way valve on Dispenser Nozzle, watch right hand gauge go
to -0- psi and
measure how much fuel entered the beaker.
B. Go to farthest nozzle, authorize the dispenser for 30
seconds, turn off pump, open nozzle,
drain nozzle
into beaker and measure how much fuel runs into the beaker.
C. With a beaker held under LDT-890(\AF), turn on pump, watch
the left hand gauge go to
30 psi,
turn off pump, set
4-way valve to Pressure Step Test, and measure how much fuel
runs into the beaker.
12. With the pump running and the 4-way valve in the Pressure
Step Test position, the right hand
pressure gauge should
read
A. leak search pressure
B. full pump pressure
C. 40 psi
13. The definition of a catastrophic leak is
A. 5 gallons per hour at 10 psi
B. 3 gallons per hour at 10 psi
C. 3.5 gallons per hour at 10 psi
14. Using the LDT-890(\AF) Leak Detector Tester to test a VMI 99
series 2” leak detector and
having started the
submersible with pressure at 0 psi and the LDT-890(\AF) in the GPH Test
position, the right hand gauge is
holding at 21 psi. In what position is the leak detector?
A. Reset
B. Full Flow
C. Leak Search
D. Vertical
15. The left hand gauge of the LDT-890(\AF) is used to set the
pressure at 10 psi during Calibrate GPH
True
False
16. The ability of a line leak detector to find a leak is
adversely affected by
A.
thermal expansion
B.
high head pressure
C. high line resiliency (high bleed-back)
D.
all of the above
17. A manifold piping system with two submersibles, each
submersible has a leak detector installed,
both
submersibles start at the same time. How many gallons per hour are
being metered into the
piping system
when both leak detectors are in leak search?
A. 3
B. 6
C. 9
18. Step through time of a leak detector is measured with a stop
watch while watching the leak detector
A. go from full pump pressure to 0 psi watching the right hand gauge of the LDT-890(\AF)
B. go from 0 psi to full pump
pressure while watching the left hand gauge of the LDT-890(\AF)
C. go from 0 psi to full pump pressure while watching the
right hand gauge of the LDT-890(\AF)
19. An anti-siphon valve or normally closed solenoid valve should
be installed between the submersible
and the leak
detector housing (tee) of the piping coming out of the submersible on
above ground
storage tank
installations with a leak detector.
True
False
20. During a leak detector test, if a master / satellite
dispenser system is included in the piping
configuration,
testing should occur from the satellite dispenser to insure total line
leak detection.
True
False
21. If a 99 LD-3000 leak detector fails a catastrophic test and
the leak detector is unable to be adjusted
to detect a
catastrophic leak, you may remove the Leak Detector Cylinder assembly
and replace it.
True
False
22. All VMI 99 series mechanical line leak detectors may be
adjusted in the field.
True
False
23. The 99 LD-2000 leak detector is more successful detecting 3 gph leaks in high bleed-back lines
than leak detectors
without an integrated check valve.
True
False
24. When two pressure relief valves are installed in series you
add the relief pressures of each valve
to determine the holding
pressure.
True
False
25. When adjusting a VMI leak detector in the field
A. always rotate the piston assembly
in a clockwise direction, moving the adjustment the
distance equal
to 3 minutes as on a 60 minute analog watch face.
B. always rotate the piston
assembly in a counter-clockwise direction, moving the adjustment
the distance
equal to 3 minutes as on a 60 minute analog watch face.
C. You cannot adjust a VMI leak detector.
26. After installing a new VMI leak detector you should fill out
the warranty registration card and return
it to the
factory.
True
False
27. If a customer complains the submersible functions well with a
few customers but drops into slow flow
during high
volume pumping, possible problems include: obstructed submersible inlet,
worn out
submersible,
inadequate submersible horsepower. Possible solutions include:
A. clean submersible inlet
B. replace submersible
C. upgrade to higher horsepower
submersible
D. install 99 LD-2000\75 or
99 LD-2200\75 leak detector
E. All of the above
28. The 99 LD-2000\E leak detector should be considered when the
piping system
A. has extremely high head pressure
B. has extremely high bleed-back (600 ml or more)
C. has PP-1500 TCI pipe (yellow)
D. B and C
E. All of the
above
29. When testing a leak detector and the leak detector is in leak
search, in what position is the 4-way
valve?
A. GPH Test
B. Dispenser Nozzle
C. Pressure Step Test
D. Calibrate GPH
30. You may use the LDT-890(\AF) to test electronic line leak
detectors for a catastrophic leak.
True
False
31. The term “leak detector has tripped” means
A. the leak detector is in “full
flow” position
B. the leak detector has reset
to the leak search position
C. none of the above
32. A VMI 2-inch mechanical leak detector is warranted for
A. 1 year from date of invoice
B. 18 months from date of installation
C. 2 years from date of installation
33. A VMI 3-inch mechanical leak detector is warranted for
A. 1 year from date of invoice
B. 18 months from date of
installation
C. 2 years from date of installation
34. Thermal contraction does not occur in warm climates.
True
False
35. A VMI leak detector may be used with variable and
non-variable speed submersibles.
True
False
36. After completion of installation of a leak detector, it must
be tested to assure it will find a
catastrophic
leak before the station is put into service.
True
False
37. “Slow Flow” problems may occur when
A. a leak is present in the line
B. thermal contraction is occurring
C. there is excessive line resiliency
D. the packer ‘o’ ring of the pump is leaking, resetting
the leak detector
E. there is no delay or a short delay for the dispenser
solenoid valve
F. all of the above
38. Thermal contraction will occur when the temperature of the
product in the underground storage tank
is higher than the
ground temperature of the delivery line.
True
False
39. The sensitivity of catastrophic line leak detectors is
established in Federal Regulation as a device
capable of detecting a
leak of 3 GPH @ 10 PSI or greater. This means the leak orifice (hole)
is
calibrated at 10 PSI,
to flow 3 GPH. It does not mean the leak detector has to search for a
leak at
10 PSI.
True
False
40. Electronic LLD automatically starts a catastrophic line test
after dispensing operations are
completed and
the last authorization is removed. Unless otherwise instructed by
Electronic LLD
manufacturer’s
instructions, the following test protocol is followed for Electronic LLD
testing.
Circle all that apply.
A. Tag-out Lock-out procedure for all
submersible pumps involved.
B. Install LDT-890(\AF) as per
manufacturer’s guidelines in test port of dispenser or
appropriate fitting.
C. Energize submersible(s)
D. Purge line and test
equipment.
E. Take a break.
F. Calibrate a 3 GHP @ 10 PSI
leak as per LDT-890(\AF) protocol.
G. Turn LDT-890(\AF) Four Way Valve to 3 GPH Test
H. Remove authorization
from submersible
I. Wait for electronic line
leak detection system to declare leak
41. After completing the installing of the LDT-890(\AF), before the pump(s) are energized, it is
important to
check the
position of the four-way valve of the LDT-890(\AF) to prevent fuel from
being
accidentally discharged while
the operator is powering the pump(s). To ensure no flow
discharges from
the LDT-890(\AF) when the pump
starts, the operator should check the four-way
valve is
set to
A. GPH Test
B. Dispenser Nozzle
C. Pressure Step Test
D. Calibrate GPH
42. With a mechanical line leak detector installed, there is no way the submersible can start without
human authorization, potentially spraying fuel on the
installer.
True
False
43. A leak detector can take longer than 3 seconds to step
through to full flow for the following reasons:
A. Thermal contraction
B. Leak in the line system
C. Large amount of bleed-back
D. Thermal expansion
E. Fuel running through the
vent line in a steady stream
F.
A,
B, C, & E
G. All of the above
44. Using the LDT-890(\AF) leak detector tester, you are testing
an MLLD. With the right hand
gauge of the
LDT-890(\AF) reading 0 PSI, and a catastrophic (3 GPH @ 10 PSI) leak
introduced
into the line,
you authorize the pump and watch your right hand pressure gauge go from
0 PSI to
full pump pressure without any hesitation at leak search pressure.
This scenario indicates:
A. No
problem
B. Line
resiliency too high for the installed MLLD
C. Wrong MLLD
for the fuel
D. Head
pressure too high for the installed MLLD
45. Testing an MLLD with the LDT-890(\AF) in G.P.H. Test mode,
the MLLD should never
open up to full flow. How long should you test the MLLD to make
sure it stays in
leak search position?
A. At
least 30 seconds
B. 3-5
seconds
C. At least 10
seconds
46. If the opening (step-through) time of the MLLD is 40
seconds, it is acceptable to run a G.P.H.
Test for 30 seconds.
True
False
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