Epoxy-coated steel tanks
Adaptation of materials to their environment, their chemical inertness and their mechanical strength are fundamental criteria when choosing a tank. APRO Industrie epoxy-coated steel tanks meet the needs of the most demanding storage requirements, whether they be due to temperature, pH variation or the chemical composition of the liquids (chlorides, sulphates, H2S, demineralised water etc.). Our epoxy solutions combine mechanical strength, corrosion resistance, tolerance to high temperatures, longevity and competitivity.
Elaboration of our epoxies
The modified epoxies employed by APRO Industrie have been developed specifically for storage applications, in partnership with one of the world leaders of the chemical industry. These epoxies are the result of a laboratory research and development programme and thirty years of continuous improvement.
Our epoxies are therefore unique, specifically suited to the constraints of liquid storage and no equivalent is available from our competitors.
The coating of the steel sheet used on our tanks is performed in our ISO 9001 certified factories, in accordance with a rigorous and carefully controlled process.
On receipt of the raw steel, it is cut out, formed and drilled in accordance with the design elaborated by our design office.
The sheet once cut out and all the accessories to be coated are then cleaned in acid and subjected to shot blasting in order to remove all traces of rust and any impurities.
Following this preparation, the parts are then coated with their epoxy protection. The coating is achieved by electrostatic application of the modified epoxy powder followed by polymerisation at 200°C.
An overcoat of urethane, applied to the external face of the sheet, ensures additional UV protection and provides a wide range of colours.
Throughout this process, sampling tests (see the paragraph on “standards” below) and thickness measurements are performed. All these operations are conducted in a controlled atmosphere: hygrometry, dust, temperature etc.
Prior to leaving the factory, all the coated parts are tested electrically at 1100V. An electric arc is generated when the test probe encounters a discontinuity or irregularity in the coating. Parts including such discontinuities are systematically rejected, thus ensuring delivery of a “zero defect” product.
The choice of our coatings, the quality of their elaboration, and the quality tests which our products are subjected to, guarantee the unequalled anti-corrosion protection of our tanks. Coatings applied in situ, in particular, provide a significantly reduced service life and resistance compared with our coatings applied in the factory under strictly controlled atmosphere conditions.
APRO Industrie offers two ranges of epoxy-coated steels:
- An industrial range which meets most of the needs of industry and public services
- A “Severe Duty” range for the most extreme applications.
According to the liquids stored and their corrosive nature, epoxy-coated steel tanks may be sealed:
Standards and Quality
Our epoxy coatings are subject to numerous quality inspections during production and on completion, by application of the required ASTM standards in order to comply with the corpus of standards AWWA D103-97, WRAS or ISO EN12944.
These tests include:
- Exposure to a saline mist for over 6,000 hours
- Immersion for 6 months in 10% caustic soda (“industrial” range) or 40% caustic soda (“Severe Duty” range)
- Immersion for 6 months in 10% sulphuric acid (“industrial” range) or 40% sulphuric acid (“Severe Duty” range)
- Peel tests to check the adhesion of the epoxy to the steel backing
- Abrasion resistance tests
Both of our epoxy-coated ranges must pass all these tests without deterioration, and therefore satisfy more stringent requirements than those specified in standard ISO EN 12944:2007 which correspond to the most severe classes of corrosivity: class C5-i and class C5-m.
Main fields of application
- Storage of corrosive industrial effluents (pH, chlorides, etc.)
- Industrial effluent treatment tanks
- Storage of liquids (including hydrocarbons) up to 95°C
- Storage of potable water or process water at up to 95°C
- Anaerobic digesters and hydrolysis tanks (compatibility with hydrogen sulphide up to 3,000 ppm)
- Storage of chemicals
A few achievements using epoxy steel
- Clariant, digester 2,000 m3
- Recogne, Veolia, buffer tank ,2000 m3
- Sirop Routin, Veolia, buffer tanks (pH variation)
- Togo, Caterpillar, hydrocarbon storage tank
- Castelmoron, Daucy, maize juice storage tanks (pH 3, lactic acid)
- Bourg Beaudoing, Dielna, molasses storage tank 2×900 m3
- Fuji, Veolia, demineralised water storage tank
Advantages of epoxy-coated steel
- Our Epoxies have a registered trade mark
- 30 years research and development
- Perfectly suited to highly corrosive environnment (pH, temperature, chlorides, H2S up to 3,000ppm etc.)
- Capable of storing liquids which are incompatible with concrete
- Compatible with hydrocarbons
- Totally inert with demineralised water
- Up to 95° C
- “Zero defect” quality
- Maintenance free
- Considerable longevity (>30 years)
- Attractive prices compared with concrete, welded steel and moulded plastic solutions upwards of 50 m3