Enamel Technology

Enamelling is a form of corrosion protection of metals. Its protective function consists in the creation of an impermeable solid layer which isolates metal from an aggressive environment. Thus, glass-fused to steel (enameled) tanks show high resistance to climatic conditions and high chemical resistance to the effects of stored materials.

Enamel is a solid, smooth and shiny coating of siliceous melted glass in a thin layer all over the surface and on both sides of the sheet. The specific composition of the enamel is adjusted so that the resulting chemical and physical properties allow the formation of a protective coating on the metal. The enamel coating is formed by a gradual injection of enamel slurry on a sheet and baking in a special continuous furnace at a temperature above 800 ° C.

The enamel surface may have one or more layers. Due to the fact that the products of our company, ie WWTP, BPS and warehouses of all sorts of materials, require the highest degree of corrosion protection, our production program includes only high quality two-layer enamel. The priority of Vítkovice ENVI is to provide the highest quality enamel surface with superior lifetime for all our products. Both layers are made of the highest quality raw materials. The production processes of Vítkovice ENVI correspond to Western European standards.

We produce a full range of enamel surfaces on sheets of various thicknesses chosen precisely according to their purpose and customer requirements. In our assortment, we offer both highly chemically resistant enamel and enamel designed for contact with drinking water and food, the health and chemical resistance of which is declared by accredited laboratories and is continuously monitored during production.

To ensure the quality of the manufactured products, VÍTKOVICE ENVI a.s. ISO 9001 certified quality system certified by RW TŰV.

Glass-fused to steel sheets

The sheets of the shell are made of special steel Kosmalt E 300 T, which is suitable for enameling with its chemical composition and structure. The standard steel sheet thickness is 3.00 mm, 4.00 mm, 5.00 mm and 6.00 mm. Each sheet has its own serial number and the result of testing the integrity of the enamel through the PINHOLE (DEZ 4.12) or POROSCOPE (DEZ 4.13) and in accordance with DIN ISO 2746 (voltage test 1000 V) is stated in the quality certificate.



Standard colours are:

white RAL 9001, green RAL 6009, blue RAL 5013, brown RAL 8017

If a costumer requires, any other RAL colour can be provided and tank surface can be highlighted with any text or logo.

Raw material KOSMALT E 300T material with mechanical properties:

Dimensions of the basic shell sheet

Standard dimensions of the shell sheet (full-plate):

1.480 m wide x 2.755 m long

1.480 m wide x 2.820 m long (double -row)

Half plate in height (half-plate):

0.730 m wide x 2.755 m long

0.730 m wide x 2.820 m long (double-row)

Half plate in length (short-plate):

1.480 m wide x 1.346 m long


Glass Coated Tanks (/Glass Fused Tanks/Vitreous Tanks)

Aboveground Glass Coated Bolted Tanks from enameled plates are manufactured in VÍTKOVICE since 1966. With the high quality of production technology, rich experience and good references exports Company VÍTKOVICE ENVI a.s. our products and technologies to worldwide market.

The Glass Coated Bolted Tranks might be used for storage of liquid or loose materials. The Tanks are also a fundamental building element of environmental technological facilities such as Waste Water Treatment Plants (WWTP) and biogas stations.

Tank shell is constructed of double-sided coated plates bolted joints connected and sealed permanently elastic sealant. The Tank shell is reinforced by angles. The bottom consists mostly from reinforced concrete or/and bottom is steel welded or bolted from enameled plates. Accessory of the tank, which is the intended purpose of the tank are Manholes, Ladders, Platforms, Stairs, auxiliary and technological structures, piping, mixers, pumps, insulation, ground etc. The tank may be covered by a different type of roofs.

The tanks are designed in accordance with standards of EN and ISO.



  • Excellent anti-corrosion properties of the enamel
  •  Unparalleled durability
  •  Proven durability of tanks for more than 40 years
  •  High abrasion resistance and chemical resistance
  •  High variability of design solutions of Tank shell (diameter, height, pipe connections) and the placement of technological equipment (pumps, mixers, heating …)
  •  Very fast construction and Installation
  •  The possibility of rebuilding or relocating already built tanks
  •  A simple and inexpensive dismantling and recycling of end of life or usage
  •  Permanent visual inspection condition and tightness
  •  Small footprint, light weight tank
  •  Easy disassembled tanks transport at the destination
  •  Experience with installations around the world, even in extreme conditions

Individually tanks are addressed:

  • If the desired roofing
  • If the stored media assumes an increase in chemical or thermal load
  • If snow loads are expected
  • Wind speed is higher than 110 km / h.
  • Location of the tank is in a seismically active area


Loose materials:

  • limestone • cement• fly-ash• wood waste• sand and gravels• granules• salt• soot


  • potable water and drinking water• waste water• fire water• desalted water• brine• oil


  • cereals• liquid manure• dung water• liquid fertilizers• feed mixture• silage

Other Application:

  • tanks for WWTPs• tanks for Biogas station• gasholder• fermenter









Use options