Above Ground
Storage Tanks &
Tank Base Sealing
Tank Base Sealing
Types of Tank
Fixed Roof Tanks
- Least Expensive to construct
- For storing “Low Vapour Pressure”
Products ( below 2 psi. )
Tank Base Sealing
Types of Tank
Fixed Roof Tanks
- Least Expensive to construct
- For storing “Low Vapour Pressure”
Products ( below 2 psi. )
Floating Roof Tanks
- To prevent evaporation loss
- More expensive to build and maintain
Tank Base Sealing
Types of Tank
Fixed Roof Tanks
- Least Expensive to construct
- For storing “Low Vapour Pressure”
Products ( below 2 psi. )
Floating Roof Tanks
- To prevent evaporation loss
- More expensive to build and maintain
Silos
- Ash (Fly ash)
- Used for Storing “dry” products
- Variety of construction materials
Tank Base Sealing
Tank Base Construction
Tank Base Sealing
Tank Base Construction
Large Tanks
1. Trench preparation for perimeter wall
2. Reinforced concrete containment wall
1
3. First sections of tank wall positioned
Large Storage Tanks – Typical Construction
22
3
Tank Base Sealing
Tank Base Construction
Large Tanks
4. Liner installed when required
5. Sand – bitumen foundation laid
6. Tank base installed
5
4
6
Tank Base Sealing
Tank Base Construction
Large Tanks
7. Walls constructed
8. Roof welded in place
9. Tank completion
8
8
7
9
9
Tank Base Sealing
Tank Base Construction
Small Tanks
1. Foundations prepared
2. Base and plinths constructed
1
3. Tanks installed
2
3
Tank Base Sealing
Problem Areas – Tank Base

Corrosion of
tank wall and
chine angle

Determination
seal

Corrosion
of tank base
Tank Base Sealing
Problem Areas – Tank Base
Conventional methods to
seal tank base
Tank Base Sealing
Problem Areas – Tank Base

Mastics

Asphalt &
Bitumen
Tank Base Sealing
Problem Areas – Tank Base

Bonded
Rubber
Tank Base Sealing
Problem Areas – Tank Base

Steel
Skirts
Tank Base Sealing
Problem Areas – Tank Base
Corrosion at the Chine Angle
- Failure of Bitumen Seal
- Corrosion of wall / base / metal thinning
- Contents to be emptied
- Tank requires to be gas free – man entry
- Sludge needs to be removed / disposed of
- Tank needs to be lifted up
Chine Angle
Tank Base Sealing
Problem Areas – Tank Base
Corrosion at the Chine Angle
- Tank needs to be cut open for plate entry
- New base needs to be built
- Base welded into position
- Hydro Test needs to be conducted
Approx. Costs ( 90 foot tank )
- $40,000 for cutting and entry / base removal
- $8,000 for sand-bit floor screed replacement
- $10,000 for flexible liner
- $40,000 for new bottom plates
- $100,000 for inspection and Hydro Test
-------------$198,000
Plus :
- Tank cleaning / waste disposal costs
- Tank out of service for 3 months
Tank Base Sealing
Storage Tank Base Associated Problems
No grout or sealing measures
Failed grout
Tank Base Sealing
Storage Tank Base Associated Problems
Failed grout
Cracked Concrete Base
Tank Base Sealing




Conventional wisdom states:
Replace failed system with more of the same
sealants
Replace failed system with similar sealants
Switch sealing system to other conventional
sealing methods
Tank Base Sealing
unconventional
PROVEN ^ LONG TERM, COST
EFFECTIVE
SOLUTIONS ARE AVAILABLE
Tank Base Sealing



Membrane systems for long term sealing of
chine angle
Epoxy grouts for concrete ring repair and grout
sealing
Urethane coatings for tank exterior
Tank Base Sealing
Key Features and Benefits

Weatherproof & Waterproof - Prevents
ingress of water and provides long term
corrosion protection

Seamless Encapsulant – Seals around
irregular contours and is easily repaired if
accidentally damaged
Tank Base Sealing
Key Features and Benefits

Maintains High Adhesion – Ensuring long
service life

Fire Resistant Systems Available

Flexible & UV Resistant – Long lasting and
tolerant of movement through climatic
variations unlike conventional sealants
Tank Base Sealing
Key Features and Benefits

Durable & Tough – Long lasting and
tolerant of industrial environments

Microporous – Allows trapped moisture to
escape

Cold Applied – No hot work required
ensuring safety in use where fire is a
concern
Tank Inspection Requirements
API 653 ( American Petroleum Institute )
BS 2654 ( British Standard )
EEMUA 159 ( Engineering an Equipment
Materials Users Association )
PA DEP 245 (Department of Environmental
Protection)
Requirement for all Tank users to
Inspect and ensure integrity of
their Structures
Frequency :
1 Year visual / 5 Year integral
Storage Tank Containment Issues
Before repair/coating
After repair/coating
Tank Base Sealing



Maintain environmental compliance
Maintain asset integrity
Minimize headaches with preventative
maintenance
Questions?
Thank You
for your time.