PEI RP-100 Rec. Practices for Installation of Underground Storage Systems Flashcards
What is the proper way to move a tank? (PEI, Section 2.2)
lifting it, using the lifting lugs
installed by the manufacturer.
Cables or chains used to lift a tank should be at an angle from the vertical (included angle) of
no more than _____ degrees. (PEI, Section 2.2)
30
When is it permissible to use chains or cables around the tank shell in order to move the
tank? (PEI, Section 2.2)
Never
At what point in the installation procedure should the air/soap test be performed? (PEI,
Section 3.2)
immediately prior to installation
What should be done with factory installed plugs before conducting the pre-installation
air/soap test? (PEI, Section 3.2)
remove all temporary plugs and thread protectors installed by the manufacturer
What is the maximum allowable internal pressure when performing the pre-installation test
on eight foot diameter steel and fiberglass tanks? (PEI, Section 3.2)
3-5 psi
What parts of a tank should be soaped when conducting a pre-installation tank test? (PEI,
Section 3.2
Soap all surfaces seams and fittings
What is the maximum pressure allowed when air testing 12 ft. diameter fiberglass tanks?
(PEI, Section 3.2)
Recommended 3psi no more then 5 psi
What is necessary to make an air test conclusive? (PEI, Section 3.2
Soaping all fittings an seams air testing for atleast 1 hour while watching psi gauge to look for any drops in pressure an checking for bubbles
What is the recommended range for a pressure gauge used to conduct a tank air test? What
can happen if a vacuum gauge is accidentally used instead of a pressure gauge? (PEI,
Section 3.2)
Use a gauge that ranges 0-10 or 0-15psi MAX , if a vacuum gauge is accidentally used it can cause a serious accident
What device is recommended to prevent over-pressurization when conducting a tank air
test? (PEI, Section 3.2)
Pressure relief valve
What is the correct way to pressurize the interstice of a double-walled tank when conducting
a pre-installation air test? (PEI, Section 3.3)
Pressurize the interstice with air from the inner
tank. Use a third gauge for measuring pressure in
the interstice
What should be done prior to disconnecting any gauges during pre-installation testing? (PEI,
Section 3.3)
Releasing the air pressure
What types of double-walled tanks do not need to have a pre-installation air/soap test? (PEI,
Section 3.5)
Tanks with a liquid- filled interstitial space or tanks with an interstitial space with vacuum
What type of pre-installation test is acceptable for double-wall tanks with a liquid-filled
interstice? (PEI, Section 3.6)
Check the level of the liquid in the interstitial space
What type of pre-installation test is acceptable for double-wall tanks shipped from the
factory with a vacuum in the interstice? (PEI, Section 3.7)
Check the vacuum level gauge
What utilities should be located before excavating begins? (PEI, Section 4.1)
All underground utilities gas, electric, water, sewer and check for overhead power lines
- What are five factors to consider when determining the size, shape and depth of a tank
excavation? (PEI, Section 4.1)
a)
b)
c)
d)
e)
Tank manufacturer install instructions, Stability of soil requirements for compacting bedding, backfill material, space for placing associated equipment, depth of cover
Why do excavation cave-in situations require the use of additional backfill? (PEI,
Section 4.1)
Materila that falls into the hole cannot be used as backfill
In the absence of local building codes or regulations, what is the minimum distance an
excavation should be located from the base of adjacent structures or property lines?(PEI,
Section 4.2)
45 degrees from the base of tank to a point 5ft from line or building foundation
What are five factors to consider when determining the depth of a tank excavation? (PEI,
Section 4.3)
Tank diameter, bedding thickness, hold down pad, depth of cover, slope and length of piping
To provide a firm foundation, backfill material serving as bedding for the tank should extend
how far beyond the actual dimensions (perimeter) of the tank? (PEI, Section 4.3)
Set the tank on a bed of backfill material 1 ft thick that extends 1ft beyond the ends and sides of tank. place at least 2ft of backfill between adjacent tanks and between tanks and excavation walls
What is the recommended thickness of bedding material over a concrete hold-down pad
when a steel tank is to be installed? (PEI, Section 4.3)
UX
6 inches
What is the maximum burial depth for fiberglass tanks? (PEI, Section 4.6)
7 ft
What determines the maximum burial depth for steel tanks? (PEI, Section 4.6)
Manufacturer’s recommendations is what you go with but
5ft is the standard for steel tanks
At what point in the installation procedure should a tank be ballasted? (PEI, Section 5.2)
after backfilling to the level of the top of the tank until piping is in place and backfilling and paving are complete
What type of testing should not be done after a tank has been ballasted with product? (PEI,
Section 5.2)
apply a vacuum to the primary tank
What types of backfill material are acceptable for steel or composite (fiberglass-clad steel)
tanks? (PEI, Section 5.4)
clean, washed, well-graded sand, crushed rock, or pea gravel
What should be the maximum particle size for backfill material for a steel or composite
tank? (PEI, Figure 5-2
1/8 inch and a maximum size of 3/4 inch.
What is the minimum thickness of the bedding material for a steel or composite tank when a
hold-down pad is not used? (PEI, Section 5.5)
12 inches
What are the standard backfill materials for fiberglass tanks? (PEI, Section 5.6)
1/2” crushed stone 3/4 pea gravel
What is the minimum thickness of the bedding material for a fiberglass tank whether or not
a hold-down pad is used? (PEI, Section 5.7)
UX
12”
For what portion of the tank is special care in placement and compaction of backfill
required? (PEI, Section 5.8, Figure 5-5)
Lower quadrant
What is the minimum spacing allowed between the tank and excavation walls? What is the
minimum spacing allowed between adjacent tanks in the same excavation? (PEI, Figure 5-5)
2’
What is the purpose of measuring fiberglass tank deflection during installation? (PEI,
Section 5.9)
To make sure the backfill is correct
In what types of soils should filter fabric be used? (PEI, Section 5.10)
Unstable soils , bogs , swampy areas
What types of materials does filter fabric separate when installed? (PEI, Section 5.10)
Fine sand particle from migrating to voids
Why must extra caution be utilized when filter fabrics are used to line an excavation? (PEI,
Section 5.10
Filter fabrics may mask early
signs of cave-ins during construction.
What is a filter fabric and what does it do? (PEI, Section 5.10)
To prevent soil migration and
loss of tank support, use filter fabric to separate backfill
materials from surrounding soil.
What must not be used to support cribbing, bracing or blocking used to support manholes
and street boxes during storage system construction? (PEI, Section 5.1
Large rocks or debris left in the excavation
In what types of locations should provisions be made to keep tanks from floating? (PEI,
Section 6.1)
Tank straps installed in High water table location
Additional forms of anchoring are usually not required if the tank burial depth is at least
what percent of the tank diameter? (PEI, Section 6.1)
60 percent
If the native soils are impervious, (that is, the soils do not allow water to pass through them
very easily) what can happen that might cause a tank to float out? What is this effect called?
(PEI, Section 6.1)
Excavation fills with water that will cause a bathtub effect
How do all tank anchoring methods offset buoyancy forces? (PEI, Section 6.4)
Interesting the amount of pressure of back fill material.
What are deadman anchors? Where must deadman anchors be placed in relation to the tank
being anchored? (PEI, Section 6.4)
anchor bolts, turnbuckles, or wire
cables and clamps. End to end of each deadman
Using the guidelines presented in this document, calculate the width, length and thickness of
a concrete bottom hold down pad if the tank to be anchored is eight feet in diameter and
26 feet long? (PEI, Section 6.4)
Pad will be 10 feet wide by 28 feet long
Under what circumstances should a tank be set directly on a concrete bottom hold-down
pad? (PEI, Section 6.4)
Never it should have filled between pad and concrete bottom
What things must be calculated for each tank installation? (PEI, Section 6.4)
The depth of the tank and back fill
What should anchor straps for steel tanks be made of? What should not be used as anchor
strap material for steel tanks? (PEI, Section 6.5)
Straps for steel tanks should
be either nonmetallic or flat steel. The use of wire ropes or round bar is not acceptable
What must be done to steel straps used to anchor steel and composite tanks to ensure the
proper operation of the corrosion protection system? (PEI, Section 6.6)
Electrically isolate straps for
steel and composite tanks from the tank surface to ensure
the proper operation of corrosion-protection systems.
Straps may be nonmetallic, fully encapsulated, or isolated
with material placed between the strap and the tank. Iso-
lating materials must be nonconductive, compatible with
the materials stored, and suitable for use underground.
What are the required dimensions (thickness, width, length) of insulating materials used to
separate anchor straps from steel and composite tanks? (PEI, Section 6.6)
at least 1/8 inch thick, wider
than the strap, and extend 1 foot below the widest part
of the tank.
What materials are NOT acceptable for isolating anchor straps from steel and composite
tanks? (PEI, Section 6.6)
Roofing felt and expansion-
joint material
What type of anchoring device should be secured through reinforcing in the deadmen? (PEI,
Figure 6-4)
Use anchor bolts,
turnbuckles, or wire cable and clamps to secure tank
anchor straps to anchor points.
When installing and attaching tank anchor straps, what should be considered regarding:
- Method of attachment? (PEI, Section 6.7)
- Tightness? (PEI, Section 6.7)
- Cleanliness? (PEI, Section 6.7)
- Electrical isolation? (PEI, Section 6.7)
- Corrosion protection? (PEI, Section 6.7)
Secure tank straps to
anchor points with anchor bolts, turnbuckles, or wire
cables and clamps.
Straps should be tightened firmly but not over tight
Coat exposed metallic
hardware with dielectric material to retard corrosi
What is the purpose of a containment manhole? What should happen to liquids that may
accumulate in containment manholes? (PEI, Section 7.2)
to contain and prevent spills or leaks during fuel delivery, preventing environmental contamination and potential hazards , there should be a drainage or a hand pump to pump back into tank
What are the two types of overfill prevention that are commonly used? (PEI, Section 7.3)
Overfill alarm box an overfill valve
What must double-walled piping be connected to in order to achieve full secondary
containment? (PEI, Figure 8-1)
To achieve full secondary containment with double-walled piping, the annular space (the space between the inner and outer pipes) must be connected to a monitored containment sump
What safety precaution should be taken before working in manways (as well as piping
sumps, dispenser sumps and other enclosed spaces)? (PEI, Section 8.6)
Inspection for any leaks
What do Environmental Protection Agency (EPA) regulations require for all new
underground storage tank systems? (PEI, Section 9.1)
EPA regulations require proper installation, protection from spills, overfills, and corrosion, leak detection, and proper closure, along with reporting, record-keeping, and financial responsibility requirements.
Why is the use of vapor sensors in interstitial spaces not recommended? (PEI,
Section 9.2.1.2
Cause it doesn’t detect water that could enter the interstice
What is hydrostatic monitoring? (PEI, Section 9.2.2.1)
Using a liquid at a set level to determine change or potentially a leak
On what types of piping systems is leak detection required? (PEI, Section 9.3)
All pressurized piping systems
On what type of piping system should an automatic line leak detector be installed? (PEI,
Section 9.5)
Pressurized underground lines
What are five specific material requirements for storage system piping components? (PEI,
Section 10.2)
a)
b)
c)
d)
e
A-Be fully compatable with product stored
B-Be comparable with underground environment
C-be resistant to normal operating and testing pressure
D-have sufficient strength to withstand the stress produced during construction and subsequent operation
E-be isolated from the ground, be constructed of non corrosive material, or be coated and cathodically protected
What should be avoided when laying pipe? (PEI, Section 10.4)
Avoid traps and crossing piping
Why should pressurized piping be purged of air before it is tested or placed in service ? (PEI,
Section 10.4
Vapor pockets may have an adverse reaction to testing results, leak detection devices, and effociency and operation of product piping
Piping trench dimensions should allow for:
- At least ______ inches of bedding. (PEI, Section 10.4)
- In traffic areas, at least ______ inches of compacted backfill and paving between the top
of the piping and grade. (PEI, Section 10.4)
- A uniform slope of at least ___________ per foot. (PEI, Section 10.4)
- The distance between piping runs should be __________ times the pipe diameter. (PEI,
Section 10.4)
- At least ______ inches clearance between the trench walls and the piping. (PEI,
Section 10.4)
6
18
1/8” per foot
2x diameter
6 inches
What is the minimum required clearance between the bottom of a submersible pump and
the tank bottom? (PEI, Figure 10-2)
4 inches
What type of pipe sealant (dope or cement) should be used with threaded piping
connections? (PEI, Section 10.7)
One that is compatable with the piping material and product stored
What is the minimum standard for metallic piping to be installed underground? For metallic
fittings and couplings? (PEI, Section 10.8)
Schd 40 factory wrapped or sealed
Extra heavy couplings
When making a transition from steel to nonmetallic piping, join steel threads
to nonmetallic threads. (PEI, Section 10.9)
Female steel thread to non metallic male thread
What can happen if dull pipe-cutting dies are used to thread metallic piping? (PEI,
Section 10.7)
Dull dies can may tear threads and a tight seal becomes impossible
Where should vent outlets be located? (PEI, Section 10.12)
Away form building openings, air intakes, and property lines above ajacent rooflines an canopies: and high enough above grade to ensure vapors discharged will not produce fire or safety hazards
When installing an emergency shutoff valve, where should the shear section be located?
(PEI, Section 10.16 and Figure 10-4)
The shear valve should be level with the top of dispenser island and that moving parts are not obstructed. Valve should be securly anchored
Under what circumstances should unions be installed underground? What type of union
should be used? (PEI, Section 10.8)
250/300# ground joint unions and provide access for service.
What should be done to dispensers, submerged pumps and other metallic components that
are not intended to be protected by the cathodic protection system provided for the piping?
(PEI, Section 10.8)
Electrically Isolate dispensers, sub pumps, check valves, tanks or other metallice components if not being protected by cathodic protection system provided for piping
Where should all flexible piping connections be made? (PEI, Section 10.10)
Within the confines of containment sump
How should flexible piping be installed? (PEI, Section 10.10)
With strict accordance of the manufacturer installation instructions, Do not interchange piping and couplings from different manufacturers. Install Flexible piping at low temperatures, avoid stretching or kinking, use continuous lengths between containment sumps, and may require different trenching configurations that rigid piping
What should be done to avoid product leaks into the environment and groundwater or
rainwater infiltration into sumps? (PEI, Section 10.11)
To avoid leaks into the environment or groundwater make all sump penetrations liquid tight.
What piping component offers a convenient means of providing flexibility in piping? (PEI,
Figure 10-5)
Flexible connectors
When conducting an air/soap test on new primary piping: (PEI, Section 11.1)
- What is the minimum test pressure?
- How long should the pressure be maintained?
- Where should the soap solution be applied?
At 50psig or manufacturer’s recommendations for 1 hour. Soap should be applied to all fittings, joints, and piping surfaces and inspect for bubbles
What should be done with lines that have held product prior to testing them? (PEI,
Section 11.1.2
DO NOT test lines with air that have held hazardous or flammable or combustible liquids or vapors unless they have been purged and made safe beforhand. If purging is not feasible use inert gas such as nitrogen or helium
Piping should be from tanks and dispensers prior to pressure testing. (PEI,
Section 11.1.2
Piping from tanks and dispensers should be isolated before air testing. They need to be purged and or inerted
What are the minimum test pressures when conducting an air/soap test on new secondary
containment piping: (PEI, Section 11.2.1)
- For fiberglass piping that operates at atmospheric pressure and uses clamshell
termination fittings?
- For fiberglass piping that uses flexible termination fittings?
- For flexible secondary piping?
Fiberglass test at 10 psig
if flexible termination fittings are used test at 5psig
For flexible secondary piping tes at 5 psig
What must be used to protect steel underground tanks and steel piping from corrosion? Do
tanks and piping constructed of corrosion resistant materials require this type of protection?
(PEI, Section 12.1)
Cathodic Protection, however tanks made with corrosion resistant materials do not require cathodic protection
What must be maintained in order to prevent loss of protection in galvanic cathodically
protected tank systems? (PEI, Section 12.5)
Electrical Isolation
On what type of cathodic protection system should components not be electrically isolated?
(PEI, Section 12.5)
components of impressed current systems
Why are factory installed corrosion protection coatings generally more effective than field
applied coatings? To which components should the use of field applied coatings be limited?
(PEI, Section 12.4)
Factory installed corrosion coating is done under controlled conditions and improves quality and minimizes defects to coating
Field coating should be limited to exposed threads, fittings, and areas damaged from handling and fabrication
Why can small exposed surfaces on coated structures corrode rapidly? What are these small
coating flaws called? (PEI, Section 12.4)
They can corrode rapidly due to high concentration of electrochemical activity. Cathodic protection is essential for protecting coating flaws
These small coating flaws are also known as Holidays
When installing galvanic anodes for corrosion protection: (PEI, Section 12.6)
- What metals are galvanic anodes usually made of?
- What must be done with the copper lead wire on a field installed anode?
- What must be done with the waterproof packaging?
NOTE: While waterproof packaging such as plastic wrapping must be removed, the packaging holding the
anode backfill (a gray powdery material) must not be damaged.
- What must be tested for continuity?
- How should galvanic anodes be installed?
- Should the anode lead wire be used to lower the anode into a hole?
Magnesium or zinc
What information does the anode current output measurement provide? (PEI, Section 12.8)
The anode-current output
measurement provides information about the level of pro-
tection being provided and the projected life of the anode.
Buried wiring for underground storage tanks must be coated with . (PEI,
Section 12.9)
Coat structure/wire connections with
insulating material that is compatible with structure coat-
ings and wire insulation.
How do impressed current cathodic protection systems work? (PEI, Figure 12-2)
controls the corrosion of a metal surface by making it the cathode of an electrochemical cell.
In the absence of a specific plan, where should galvanic anodes be located in relation to the
piping they are protecting? (PEI, Section 12.11)
installing at least two
magnesium anodes vertically, 3 to 5 feet from the center
of the pipe trench with the top of the anode below the
level of the piping.
Why should two anodes be used to protect buried piping, even when one is probably
enough to provide the required protection? (PEI, Section 12.11)
In case one fails
When testing galvanic cathodic protection systems, what voltage relative to a copper-copper
sulphate reference electrode is usually sufficient to provide corrosion protection? (PEI,
Section 12.14 and Appendix B, Section B.5)
0.85vokts
What are five ways that electrical work can cause environmental problems? (PEI,
Section 13.1)
a)
b)
c)
d)
• The defective installation of tank-monitoring or
leak-detection system wiring may allow a release
to remain undetected.
• Conduit or other electrical apparatus placed against
a surface that is protected against corrosion may
cause damage to the coating or cathodic protection.
• Electrical-equipment installers may damage the
tank or piping while excavating, driving stakes, or
otherwise performing their work.
• Galvanic cathodic protection of metallic tanks or
piping is impaired by grounding.
• Failure to make the entry point of electrical conduit
into tank-top and dispenser sumps liquid-tight can
result in the release of product into the environment
or the infiltration of water into the sump, causing
leak-detection systems to false alarm.
How much distance should separate electrical conduit and underground piping? (PEI,
Section 13.2)
6”
Before placing a storage system in service, what testing should be performed: (PEI,
Section 14)
- To the cathodic protection system?
- To a single-walled tank and piping?
- To a double-walled tank and piping system?
