Back in 1999, when an Icelandic fish farm decided that it was time to refurbish its pumps, it was decided to protect them by coating them internally with an epoxy coating system. Developed to improve pump efficiency, eliminate corrosion and decelerate erosion, 15 years later the original pumps that were coated in 1999 are still in service today.
Located in the Southwest corner of Iceland beside the Atlantic Ocean is one of Stofnfiskur’s salmon broodstock farms. This farm located in a place called Vogar was originally established in 1986 produces Salmon Ova which are sold to domestic and International hatcheries for fish farming.
The facility houses 25,000m3 tanks in 10 massive sheds used for the breeding of salmon and production of salmon ova. Each tank holds tens of thousands of litres of water delivered constantly by an army of centrifugal pumps.
Loss of efficiency
Stofnfiskur started to work with Velar, the Distributor of Belzona products in Iceland, in 1999 after a presentation of Belzona products done by Velar. Previous experience had shown that after a period of two years, the pumps which were in constant daily use recycling the water in the tanks became corroded and lost efficiency. Following discussions with Ragnar Karlsson, of Velar, it was decided that to protect the pumps and extend their working lives, they would be coated internally with Belzona 1341 (Supermetalglide) before entering service as part of a preventative maintenance programme. 15 years later the original pumps that were coated in 1999 are still in service today.
Belzona 1341 is an epoxy coating system developed to improve pump efficiency, eliminate corrosion and decelerate erosion. Due to its ultra-smooth, self-leveling and hydrophobic properties as well as its low surface energy, it has been proven in independent tests to reduce turbulence and surface tension. At the same time, the coating will protect the component against future corrosion, meaning that its immediate effects on performance will be maintained over a long period, reducing power consumption and saving operating costs. These friction losses translate into efficiency increases and ultimately in a cost saving for the customer. On new pumps, efficiency increase as much as 7% has been tested and recorded.
In the case of Stofnfiskur, this cost saving was significant. They currently have 154 pumps working in all their Fish farm stations consuming approximately 1MW of electricity per month. 80% of these pumps handle the water in the tanks and are between 0.55-30 kW. The rest are borehole pumps used to extract clean and in some cases slightly salted water from beneath the surface.
The largest borehole pump is 24 in with 169 kW pump. Due to the high risk of disease in the produced ova, clean media is constantly drawn up by this and the other borehole pumps ensuring a constant fresh supply of media whether being clean fresh water or pure sea water. Here also, the use of the coating has helped the facility maintain its high cleanliness standards. Belzona 1341 carries several approvals for contact with potable water and in food production including WRAS, NSF and FDA approvals.
Coating of pump internals using Belzona 1341 is carried out by Velar in their workshop in nearby Reykjavik. Here, new and old pumps are refurbished using Belzona materials. Following strip down, the pump internal components which require repair or coating are grit blasted carefully to prepare the metal. The prepared metal is then cleaned and the Belzona materials applied. Once coated, pumps are reassembled and sent back to service. To get the best efficiency in the pumps the bronze impellers are coated as well, leaving only the AISI 316 stainless steel shafts uncoated, eliminating the chance for galvanic corrosion to affect the pumps internally.
Being able to supply their customers quickly and efficiently is a large part of the service offered by Velar. As part of a complete supply and apply package, Velar offer Belzona materials as well as pumps and parts that are constantly in stock to ensure customers can get what they need on short notice.
With the increasing cost of energy, new pumps coated with Belzona 1341 are expected to provide a return on investment in less than a year and will continue to provide valuable savings by maintaining a high efficiency levels for many years to come.