Metal or thermal spraying is a technology, which protects or extends the life of a wide variety of structures in the most hostile environments and in situations where coatings are vital for safety and performance. Thermal spraying is carried out in a wide range of anti‐corrosion or engineering markets. Typical applications include the spraying of ships, trawlers and other ocean-going vessels.
The anti‐corrosive properties of the metal spraying process are widely recognised in the shipping and marine industry, where steel super structures and vessels are subjected to very damaging corrosion from the sea and salt laden air of the world’s shipping and fishing industries.
In the petrochemical industry Corrosion Under Insulation (CUI) in pipeline systems consumes a significant percentage of the maintenance budget. A large portion of this money is spent on expensive items such as external piping inspection, insulation removal and re-installation, painting and pipe replacements. CUI prevention strategies provide long term and reliable prevention of CUI that move towards inspection-free and maintenance-free piping systems and significant maintenance cost reductions.
Coating with TSA (Thermal Sprayed Aluminium), using Metallisation flame spray equipment is one method that a number of operators within the petrochemical industry have adopted. TSA is found to be a cost effective solution compared to other systems when reviewed over the lifetime of the facility.
Metallisation flame spray equipment has been used to protect a BP Clair Ridge offshore oil platform from corrosion. The 168 metre high platform is installed in the North Sea west of the Shetland Isles, Scotland.
Clair Ridge jackets have seven storage tanks, two drill water tanks and a base oil tank, in the Drilling Production (DP) jacket, and four diesel tanks in the Quarter Utility (QU) jacket. The project specified the jackets to be metal sprayed, to protect from corrosion, using Arc spray equipment. The system for the internal storage tanks was to be sprayed with 200–300 microns Thermal Sprayed Aluminium (TSA), the drill water tanks were to be sealed with aluminium silicone and the base oil and four diesel tanks were to be left unsealed.
RFI Screening Limited, specialist surface treatment engineers, has opted for Metallisation MK61 flame spray equipment to metal spray a 40 tonne generator rotor with fine silver.
The generator rotor, which is a combination of electrical, mechanical and manufacturing components, is regularly exposed to hard mechanical stress and high temperatures, while being subjected to electrical voltage and current. Over time this stress can lead to breakdown, costly repair and maintenance and possibly inconvenient downtime. To maximise the lifetime of of the generator rotor, RFI Screening was contracted to metal spray it, using the flame spray equipment.
In the agricultural industry, there’s a necessity for cutting, slashing and ploughing, which means equipment and components are subject to abrasive and corrosive conditions. Maintenance is essential, and sadly, the costs can add up.
Metal and thermal spray coatings, along with hard-facing, can provide an economical solution for the wear and corrosion of agricultural machinery and components. Metal spraying provides increased resistance to corrosion and wear, resulting in extended life and increased performance.
It can also help to ensure crop irrigation pumps can withstand the hardness and ph values of water and fertilisers by applying ceramics to pump seal areas. This repairs and protects OEM components.
The dictionary definition of galvanise is ‘to coat (iron or steel) with zinc’. Hot dipped galvanising is a well-established process used to protect steel from corrosion by applying a layer of zinc.
Steelwork is immersed briefly in molten zinc with layers, usually of an even thickness, dense and metallurgically bonded to the steel. Thickness is typically .002-.006 in (50 – 150u). There is however, another process that can be used to coat steel with zinc.
Metal spraying using arc spray or flame spray is an alternative method of coating with zinc (or many other materials) to hot dipped galvanising. All methods of metal spraying involve the projection of small molten particles onto a prepared surface, where they adhere and form a continuous coating.