New
Tanks |
Existing Tanks |
Existing
Floor |
| New Floor |
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Single
Floor |
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Double
Floor |
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Wire or ribbon anodes (typ. MMO or platinum clad) laid out in a continuous pattern |
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Min. 150mm (6”) clearance required |
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For use with or without a liner |
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Close, distributed anode array ensures that current reaches the entire tank floor |
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Long service life |
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Small dia. platinum clad or MMO anodes in a secondary layer of coke |
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Min. 300mm (12”) clearance required |
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For use with or without a liner |
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Primary anodes with surrounding coke breeze ensure long anode life & low driving voltage |
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1:1 proportioned anode floor array ensures even current distribution to entire tank floor |
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May be used on either ambient temp. or heated tanks |
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Small dia. platinum clad or MMO anodes packaged in calcined petroleum coke breeze |
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Min. 450mm (18”) clearance required |
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For use with or without a liner |
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Pkgd. anodes with surrounding coke ensure long anode life and low driving voltage |
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Distributed anode array ensures that current reaches the entire tank floor uniformly |
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Under-Floor “Old Floor”
(Patented) |
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The old floor is used as the anode during tank floor replacement |
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Min. 100mm (4”) clearance required |
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For use with or without a liner |
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Using old floor as an anode minimizes cost |
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Very uniform current density |
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Very long life |
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Ideal for use where original tank floor was installed with a liner thus precluding typical CP applications |
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Typ. high purity zinc anodes in a select backfill of gypsum, bentonite & sodium sulphate |
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Magnesium anodes may be substituted in higher resistivity soils |
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For use with or without a liner |
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No external power supply required |
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Very low maintenance & long service life |
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Ideal for smaller diameter pre-fab tanks or for tank floors that have been externally coated |
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| Under-Floor Directional Boring |
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Wire or ribbon anodes (typ. MMO or platinum clad) surrounded by coke breeze columns, installed in horizontal boreholes, directionally bored under the tank |
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For use without a liner |
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Distributed anode array ensures that current reaches the entire tank floor uniformly |
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Ideal for protecting the entire floor on existing tanks |
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| Under-Floor Slope-Drilled |
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Small dia. platinum clad or MMO anodes pkgd. in calcined petroleum coke breeze installed in sloped boreholes augered beneath the tank |
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Anodes installed under the periphery of the tank floor |
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For use without a liner |
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Design flexibility accommodates congested areas |
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Ideal for protecting extended areas of tank floor |
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Tubular type HSCI anodes installed around the tank periphery |
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A variety of other anode materials & styles are also available |
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Min. soil cover of 3m (10’) required |
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For use with or without a liner |
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Design flexibility accommodates various tank sizes, congestion & current requirements |
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Provides low circuit resistance & more uniform anode current discharge |
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Ideal for areas with a large overburden of clay, silt, or sandy soil over bedrock |
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Tubular type HSCI anodes are typical and have a proven track record in this service |
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A variety of other anode materials & styles are also available |
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Requires vent pipes or covers at grade |
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For use without a liner |
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Design flexibility accommodates various tank sizes, congestion & current requirements |
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Minimal excavation |
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Ideal for areas with clay, silt, or sandy soil that is relatively free of rock |
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