Storage tanks, whether they are intended for water storage, chemical storage or any other liquid require durability and compatibility. Whilst many storage tanks have these qualities, they are susceptable to leaking. In such instances. a new tank might be required, but in reality a re-lining of the internal surface with a resin-based lining system like GRP or polyurethane is highly desirable. This could result in significant cost savings.

1. STORAGE TANKS:
REPLACEMENT OR RE-LINING?
Cost-analysis for tank re-lining: how you can save money
by re-lining instead of replacing an existing tank
Stephen Bowen, Managing Director, Strandek GRP Systems

2. WWW.STRANDEK.CO.UK
Contents
Ø Understanding storage tanks
Ø Why do storage tanks fail?
Ø How to prevent storage tank failure
Ø How much is a resin lining system?
Ø Types of resin-based tank linings
Ø Liquids contained in storage tanks
Ø Types of resin-based tank linings
Ø Concrete storage tanks: replace or re-line?
Ø GRP storage tanks: replace or re-line?
Ø Steel storage tanks: replace or re-line?
Ø Example: fibreglass (GRP) Water Tank Lining
Ø References and Regulations
Ø Summary
Ø About Strandek
Ø Contact Us

3. • Storage tanks are considered a form of ‘Primary Containment’
• Storage tanks are designed to contain and secure a variety of liquids,
from potable drinking water to sulfuric acid and fuel
• Their purpose is to prevent liquid from:
• Exiting the vessel and escaping into the outside environment
• Being exposed to the internal environment
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Primary containment
Understanding Storage Tanks
• In the UK, storage tank regulations are generally detailed by the Health & Safety Executive (HSE).
• Regulations are specific to the components being stored and can be summarized as:
• Storage of flammable liquids in tanks HSG176 – HSE
• Storage of acids: Guidance on the storage of hydrochloric acid and nitric acid in tanks
• Bulk LPG storage tank: Safety of your LPG storage tank
• Other more specific guidance is available for tank linings for drinking water storage
Defining storage tank regulations

4. Beyond impact, such as collisions, falling debris and other
physical stressors, the breakdown of storage tank surfaces is a
surface-localized reaction and interaction between the liquid
contained in the tank and the internal substrate exposed to that
liquid.
Classic examples of tank failure are dependent on the substrate
of that tank.
• Concrete tanks: cracks and ingress, particularly in more
porous versions
• Steel tanks: corrosion (even when galvanized if the external
layer is scraped away)
• GRP tanks: cracks, fractures, breakdown
The inclusion of a robust tank lining system is an effective
means of preventing tank failure.
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Why do storage tanks fail?
Why Do Storage Tanks Fail?
Vessels lined with sheeted systems or those using an incorrectly applied polymer are also prone to failure. Whilst these systems
are cheap and often quick to install, they are more susceptible to leaking than a robust lining.
Low-quality liners – another reason for tank failure…

5. Storage tanks require careful design, installation, inspection and often ongoing, scheduled
maintenance as follows:
• Design: storage tank size, substrate compatibility and location are major factors. Consideration of
an appropriate lining is also recommended for substances where the main tank substrate is
incompatible or susceptible to damage.
• Inspection: identification of damaged or degraded surfaces within the tank, evidence of leaking or
contamination of liquids being stored. An assessment of the tank lining is also performed.
• Maintenance: this could involve some minor repairs, the checking or electronic parts and
components. Usually performed following an inspection.
• Refurbishment & Repair: involves the potential re-lining of an existing lining that may have been
damaged. Often performed in response to an incident or a
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Considerations on how to keep your storage tanks safe and compliant
How to Prevent Storage Tank Failure
According to the HSE’s guidance on Plant Codes, liners should be selected based on the liquids being stored.
“Where carbon steel will not resist expected corrosion or erosion or could cause contamination of the product, vessels may be lined with
other metals or non-metals. A lined vessel is usually more economical than one built of solid corrosion resistant material. Metallic
liners are installed in various ways… Non-metallic liners may be used to resist corrosion and erosion or to insulate and reduce the
temperature on the walls of a pressure vessel.”

6. What is the cost per kg?
The price (£) for 1 kg of the tank
lining indicates the most cost-
effective system.
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Why is it important?
The cost per kg ratio enables
a direct comparison to other
substrates and materials.
How does GRP perform?
Epoxy resin is around 1.4 times
more expensive than polyurethane
and fibreglass-based systems
Source: http://web.mit.edu/course/3/3.11/www/modules/props.pdf
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Epoxy Resin PolyurethaneFibreglass (GRP)
Costperkgofresin(£/kg)
How Much is a Resin Lining System
Most resins are similarly priced. The
overall lining cost also depends on
the number of layers, thickness and
additives required.

7. A range of different storage tanks exist:
• Fixed-roof storage tanks
• External floating roof tanks
• Floating roof tanks
• Domed external floating roof tanks
• Horizontal tanks
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Lining = inner barrier
Coating = outer barrier
Substrate
Liquid being contained
Top-down view of a primary containment vessel
Resins can be applied to tank surfaces for enhanced protection
Types of Resin-based Tank Linings
Resin-based linings for storage tanks are applied to the inside of
storage tanks, protecting the inner surface of the tank substrate
from being damaged and degraded.
These can be made from glass fibre, concrete, certain
types of steel and other specialist components. Resin
can be bonded well to each of these.

8. Fuels and oils: petrol, diesel, motor oil
Food processing: vegetable oils, dairy, soft drinks
Acids: sulphuric acid, hydrochloric acid, lactic acid
Alkalis: sodium hydroxide, sodium carbonate, potassium
hydroxide, potassium carbonate.
Water: wastewater, treated water, sewage
Breweries/distilleries: beer, whiskey
Solvents: ethanol, acetone, methanol
Agriculture: fertilizer, diesel, water
A wide range of liquids are stored in storage tanks…
Liquids Contained In Storage Tanks

9. EPOXY RESIN SYSTEMS
• Good mechanical strength
• Can be combined with aggregate
• Low flexibility – suitable for
demanding environments
• Chemically resistant to a wide
range of substances
• Fully impervious, highly durable
POLYURETHANE RESIN SYSTEMS
• Excellent flexibility – up to 400%
elongation capacities
• Seamless and versatile
• Chemically resistant to a wide
range of substances
• Marginally more expensive than
epoxy
FIBREGLASS (GRP) SYSTEMS
• Composite system made from
glass fibre mat and polyester resin
• High strength-to-weight ratio
• Low cost vs. other systems
• Chemically resistant & impervious
to a range of liquids
• Good elongation & flexibility
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Resins are multi-functional, applied in situ and highly versatile forms of tank surface
protection, inside or out. Resins utilised for protective linings are very popular in the in the
construction industry. Classic examples utilised centre on epoxies, polyurethanes and
fibreglass-based composites.
Some of the resins used to protect tank surfaces
Three of the most popular resins used for storage tanks linings are listed below. Each 3 has
different properties that offer favourable performance, depending on the application.
Resin-based tank lining systems
Types of Resin-based Tank Linings
Fibreglass laminating step
Epoxy tanks coating

10. Option 1: Buying a new concrete storage tank
• Expected lifetimes: 10-20 years
• Susceptible to leaks, cracks, liquid ingress and microbial
contamination
• Receive low durability linings: EPDM, thin polymers, etc.
• Concrete tank replacements typically several times more
expensive than a lining refurbishment
Option 2: Relining a concrete storage tank
• Multiple lining options, from GRP to epoxy
• Expected lifetime with linings: 15 -20+ years depending on
type of liquid exposure and environment
• Cost savings of up to 57-62% versus new concrete tanks
• High-performance linings: bespoke and customized for each
application
Concrete Storage Tanks: Replace or Re-line?
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Fibreglass (GRP) Lining
Epoxy Lining
Polyurethane Lining
Tank Replacement
£-
£5,000
£10,000
£15,000
£20,000
£25,000
10,000 20,000 50,000 80,000
Concrete Water Tank: Replacement vs. Relining Costs
Fibreglass (GRP) Lining
Epoxy Lining
Polyurethane Lining
Tank Replacement
Storage Tank Capacity (Litres)
StorageTankCost(£)
Tank replacements are much more expensive
than re-lining systems irrespective of size

11. Option 1: Buying a new fibreglass (GRP) storage tank
• Expected lifetimes: 10-20 years
• Susceptible to leaks, cracks, liquid ingress and microbial
contamination
• Receive low durability linings: EPDM, thin polymers, etc.
• Replacing the tank can cost up to 5x more than a re-lining
refurbishment
Option 2: Relining a concrete storage tank
• Multiple lining options, from GRP to epoxy and polyurethane
• Expected lifetime with linings: 15 -20+ years depending on
type of liquid exposure and environment
• Cost savings of up to 75% versus new concrete tanks
• High-performance linings: bespoke and customized for each
application
GRP Storage Tanks: Replace or Re-line?
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Fibreglass (GRP) Lining
Epoxy Lining
Polyurethane Lining
Replacement Tank
£-
£5,000
£10,000
£15,000
£20,000
£25,000
10,000 20,000 50,000
Fibreglass (GRP) Water Tank: Replacement vs. Relining
Fibreglass (GRP) Lining
Epoxy Lining
Polyurethane Lining
Replacement Tank
Storage Tank Capacity (Litres)
StorageTankCost(£)
Tank replacements are much more expensive
than re-lining systems irrespective of size

12. Option 1: Buying a new steel storage tank
• Expected lifetimes: 10-20 years
• Susceptible to leaks, cracks, liquid ingress and rust
• Receive low durability linings: EPDM, thin polymers, etc.
• Costs typically 4 – 5x more expensive than a lining
refurbishment
Option 2: Relining a steel tank
• Multiple lining options, from GRP to epoxy
• Expected lifetime with linings: 15 -20+ years depending
on type of liquid exposure and environment
• Cost savings of up to 80% versus new concrete tanks
• High-performance linings: bespoke and customized for
each application
Steel Storage Tanks: Replace or Re-line?
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Fibreglass (GRP) Lining
Epoxy Lining
Polyurethane Lining
Replacement Tank
£-
£10,000
£20,000
£30,000
£40,000
£50,000
£60,000
£70,000
£80,000
10,000 20,000 50,000 80,000
Liquistore Galvanised Steel Water Tank: Replacement vs. Relining
Fibreglass (GRP) Lining
Epoxy Lining
Polyurethane Lining
Replacement Tank
Storage Tank Capacity (Litres)
StorageTankCost(£)
Tank replacements are much more expensive
than re-lining systems irrespective of size

13. ü Low cost: 3x cheaper than carbon fibre
ü Versatile: compatible with concrete, wood, etc.
ü Durable & robust: multi-decade performance
ü Exceptional strength: stronger than certain metals
ü Water and chemical resistant to a wide range of
substance
ü Flame retardant: BS Class 1 & 0 476
ü UV-resistant
ü Good curing times: hardening within 24 hours
ü Bespoke: can be tailored to individual chemicals &
environments
ü Easy clean: resistant to power washing, easy to
create a hydrophobic surface
• Substrate bonding facilitated by resin primer
• Blend of polyester resin & glass fibre mat to create a laminate
• Protective topcoat comprised of WRAS-approved resin.
Fibreglass GRP linings can be
applied to a range of surfaces,
from concrete to existing GRP.
See a recent case study for a
storage tank GRP lining.
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Example: Fibreglass (GRP) Water Tank Lining
Like epoxies and polyurethanes, fibreglass is an excellent lining system
Benefits of Fibreglass (GRP) water tank linings

14. References and Regulations
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Storage tank regulations
• HSE regulations regarding primary containment storage tanks
are specific to individual liquids being stored:
• Storage of flammable liquids in tanks HSG176 – HSE
• Storage of acids: Guidance on the storage of hydrochloric
acid and nitric acid in tanks
• Bulk LPG storage tank: Safety of your LPG storage tank
• RR760 - Mechanical integrity management of bulk
storage tanks
• Glass reinforced plastic vessels and tanks Advice to users
Tank linings and coatings
• Potable drinking water: WRAS-approved resin is required
• Storage tank lining specialists
Secondary containment
• Bund linings – secondary containment systems that often
accompany storage tanks and vessels:
• Specialist bund lining contractors
• Bund lining systems
GRP linings
• Fibreglass (GRP) linings and coatings
• Fibreglass GRP bund linings
• Fibreglass GRP bund lining case study
• How to make a GRP lining
• GRP linings for concrete

15. • In most cases significantly more durable and robust than no lining or a rubber-based variant
• Both flexible and as strong as certain metals like steel yet exceptionally light
• Rust-free – chemical resistance can be tailored to every indication
• Versatile and able to bond strongly to concrete, steel, existing GRP and other substrates
• Durable and robust, with lifetimes exceeding 30 years
• Preferred by many industries, from construction to chemical processing, marine an aerospace industries
Disclaimer: these values have been compiled from a combination of academic and online resources and should not be taken as performances attainable by Strandek GRP Systems. They may not represent
the true values attainable from these materials and should not be interpreted as such.
Summary
Resin-based storage tank and vessel linings are:
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16. History
• Founded in 1976
• Specialists in cold-applied, resin-based linings and coatings, from fibreglass (GRP) to epoxy and polyurethane
Responsibility
• A strong health, safety & environmental policy
• Trained, certified and dedicated applicators
Service & Performance
• Experts in a range of resin-based composites, from fibreglass to polyurethanes and epoxies.
• Close working relationship with leading manufacturers
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Strandek: Bund Lining Specialists
Experts in surface waterproofing and chemical protection

17. Contact Us
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Steve Bowen
Managing Director & Founder
Phone: 01633 250652
Email: steve.bowen@strandek.co.uk
Paul Chapman
Senior Manager
Phone: 02920 900011
Email: paul.chapman@strandek.co.uk
Main Address
Strandek GRP Systems
Croes-Carn-Einon, Newport
South Wales, NP10 8RR
www.strandek.co.uk
Company number: 01448607
Jan Pitt
Finance & Administration
Phone: 01633 250652
Email: admin@strandek.co.uk