Given the corrosive and potentially hazardous nature of the environment, a number of variables need to be considered when selecting equipment and components for offshore applications. Fans within ventilation systems are no exception and can be found in various areas of an offshore platform, for example, compressor cooling enclosures, production platforms or gas turbine enclosures. These areas present varying degrees of hazard which the fans must be suitable for. Two important variables for consideration include the need for ATEX (non-sparking and explosion proof) variants and the surface finish of the fans.
ATEX variants are required in areas in which hazardous gases are present. One such area would include gas turbine enclosures. Given that the turbine contains gas, the main aim is to reduce the risk derived from a build-up of hazardous gases by ensuring effective ventilation, ATEX cased axial fans for both supply and exhaust of these gases are often used.
Any ATEX variants should be specified by the system manufacturer’s maintenance manuals. This will advise the zone that the components should be certified to. Zoning is based on the type of flammable material (gas and vapours or dust and fibres) and the presence of that material (continuous, intermittent or abnormal).
Industrial fans with special paint grades, coatings or hot dip galvanised processes are often specified in corrosive environments to ensure longevity of the product in use. Offshore and marine environments are classified according to their grade of environmental corrosivity which affects the components used in those environments. Moisture, oxygen, temperature, air pollution and marine atmospheres containing chlorides and dirt etc. affect the rate of corrosion of steel. Corrosion and the degeneration of stainless steel structures such as industrial fans can be limited through correct material selection, organic coating paint, good surface preparation and careful consideration of the corrosivity category.
ISO 12944-5:2007, describes the types of paint and paint system commonly used for corrosion protection of steel structures such as industrial fans. It also provides guidance for the selection of paint systems available for different environments and different surface preparation grades, and the durability grade to be expected. The durability of paint systems is classified in terms of low, medium and high. Paint grade finishes include C3 for urban and industrial atmospheres, C4 for industrial and coastal areas and C5M for marine, offshore and coastal environments.
Axair Fans works closely with innovative supplier partner Casals Ventilation to provide a wide range of medium and high pressure centrifugal and axial fans painted to marine grade specifications, available in ATEX variants.
Contact us on: 01782 349 430 to request a quote or to discuss how we can help.