INVESTMENT
PROTECTION
Corrocoat products provide engineering structures and equipment with long-term and cost-effective protection against corrosion.
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Corrocoat USA were asked to apply a surface tolerant coating system to the structural steel on a pipe bridge, on site at a coal-fired power plant in Florida. The pipe bridge, spanned a 135 foot (41 meter) diameter thickener tank, which is used to clarify or separate the solids included in recycled gypsum. The solids are transported from the recycling tanks, which are upstream in the Flue Gas Desulphurization System. Once clarified, the gypsum is refined further and then sold to a neighbouring facility who use the gypsum to make drywall board, used in houses and commercial buildings.
The client hired a firm to perform an engineering inspection in the spring and were advised to replace the severely corroded steel members, and apply a suitable corrosion resistant coating to the new and remaining members. The structural steel members were corroded as a result of a reaction with the low pH vapours, that fume up from the tank beneath.
As this tank was integral to the power generation process, the project was completed during an outage. Corrocoat USA had only 2 weeks to complete the project, which included 4,700 square feet (432 square meters) of structural steel, many of which were small angles, channels and I-beams.
Working off scaffolding, the crew executed a surface tolerant specification that included pressure washing, spot preparation using angle grinders and needle guns. They then primed with Plasmet ZF; a surface tolerant two-pack epoxy coating compound incorporating a rust inhibitor and passivator, with MIO (micaceous iron oxides) and glass flake for increased protection. This was then over-coated with Corrothane AP1.
It took 12 men thirteen consecutive days, working long hours, to complete the project to the satisfaction of the customer. The team completed the project one day ahead of schedule, an impressive feat considering the intricacies/geometries of the project.
For the past two weeks we had the pleasure of hosting our partners from Corrocoat Caspian, at our head office in Leeds. Aliya Zhumanova, Corrocoat Caspian Director, joined us with Konstantin Vassilyev, Murat Jumabekov and Kirill Slavko to undergo advanced technical training.
Our Technical Supervisor, Douglas Lynch oversaw all of the training, starting the 2 weeks off with theory-based training on corrosion, service environments, specifying products and much more.
Murat, who originally joined the company as a security guard 9 years ago, worked his way through the ranks, becoming one of the leading engineers and applicators in the field. Murat was joined by fellow applicator, Konstantin, as they continued their training with practical sessions in our coating and engineering workshops. Carrying out specialist coating applications, pipe spraying, pipe wrapping and pump disassembly, Murat and Konstantin were shown the latest techniques by our leading mechanical engineers and coating specialists and applicators.
Kirill, originally joined Corrocoat Caspian as a Sales Engineer. Recently promoted to Production Manager, Krill, as part of his training, spent time with our Coating Production Manager, Mike Walsh and other members of the Corrocoat production team, to get to grips with the intricacies of the production and manufacture of our specialist coating systems.
Following their training, our CEO, Charles Watkinson, presented the team with a certificate – it was a very proud day for the group, who had thoroughly enjoyed their time with us. We are very much looking forward to hearing from Corrocoat Caspian on the exciting projects they are continuing to undertake in Kazakhstan and how their training will be put to use to further enhance the service and results delivered to their clients.
An international marine client recently commissioned our partners in Singapore, BHM Engg Services, to refurbish and provide corrosion protection for a badly corroded sewage tank. The tank had been in service around 2 ½ years and the client requested an alternative to an epoxy paint system which had already failed having suffered from chemical attack.
Polyglass Standard; a two-pack cold cured polyester/acrylic co-polymer enhanced with flaked glass, was selected for this project. Polyglass performs extremely well in immersion environments such as marine, aqueous and corrosive chemical environments.
The team began by removing the original coating and then pressure washing the tank at their workshop. It was then grit blasted before the new coating system was applied by airless spray and brush application.
The client was extremely happy with the results and the BHM team were commissioned to refurbish and provide protection for a second tank.
The Steenbras Hydroelectric Power station was the first of its kind in Southern Africa, and to date has served the city of Cape Town for over 40 years. The hydro-electricity generated is distributed by the local (municipal) grid. Two dams are located at different elevations (300m), connected by a low-pressure tunnel through the mountain, to the high-pressure tunnel / steel penstock 3.8m in diameter, which is buried below ground to reduce environmental impact.
The penstock feeds water gravitationally through four turbines, generating 180MW of electricity for the City of Cape Town. The internals were originally coated with a thin solvent-based epoxy, which blistered. The internal lining was refurbished after 18 years in service with another epoxy lining and blistered again.
Our partners in South Africa, Cape Town, were awarded the tender for the reline of the steel section of the penstock. It took 12 months of planning, design, fabrication and testing to prepare for this challenging and time sensitive project.
SCOPE OF WORK:
COATING SYSTEM USED:
SITE CHALLENGES:
Rope Access professionals were essential to installing the customized scaffold and stair system that allowed a larger work force to work. However, some areas could only be reached via rope access alone.
Despite all of the challenges, work was completed to the full satisfaction of Corrocoat South Africa’s client.
Corrocoat USA and Corrocoat Ltd recently joined forces to supply over 25,000 litres of our high performance protective coating, Polyglass VEF in combination with bespoke lamination technology, for the internal lining of a 250ft diameter crude oil storage tank.
The client – a large oil refinery in the US, were in desperate need of a vinyl ester lining to replace the existing fibreglass coating. This had failed an inspection carried out in accordance with the American Petroleum Institute (API) guidelines. The client turned to Corrocoat USA to provide the material required to reline and protect the tank floor against future corrosion.
Corrocoat USA were able to manufacture and deliver a significant portion of the product to the client. However, due to the time constraints, Corrocoat UK were also asked to arrange production and international delivery of the remaining 20,000 litres of product required. This also included Corrocoat’s Corrofill VE and Polyglass PPV.
The logistical requirements we not insignificant and both companies relished the challenges this caused. Product supplied from the UK needed to travel by airfreight, at a time were securing cargo space was at a premium.
Marta Krause, Corrocoat Ltd Shipping Manger said; “this order was a major undertaking for both Corrocoat Ltd and Corrocoat USA. There were numerous challenges we faced in terms of the supply, manufacture and shipping of the product, but I’m pleased to say as a result of our hard work and commitment the order was successfully fulfilled, within the time constraints. We have a great international network and work very closely with our licensed partners to deliver our industry leading extra-durable, corrosion protection products worldwide. It was a pleasure to work with Corrocoat USA on this order, and a great and very rewarding team effort.”
Following the supply of the Corrocoat products, the tank floor was successfully lined and has an expected life of more than 25 years. Incredibly impressed with the service, as well as the product, the client has an ongoing contract with Corrocoat USA for the manufacture and supply of products for future projects.
Josh Tankersley, Corrocoat USA General Manager, commented; “The client was extremely impressed with the whole experience. To say that we exceeded their expectations is an understatement. The client informed me that they originally thought there was no way we would achieve what we promised, and had already prepared the organization to forgo more than $10 Million per day in lost production.”
As the developers and manufacturers of specialist coatings, Corrocoat are able to guarantee a reliable supply chain and provide abrasion resistance, erosion resistance, fluid efficiency and antifouling products to solve the world’s most demanding corrosion service environments.
Contact a member of the team today to discuss our product offering.
A raw water pump in service at a combined cycle gas turbine (CCGT) power station, required a programme of refurbishment and corrosion protection, in order to prolong its service life.
Upon arrival at our workshop, the pump was stripped down and both the casing and impeller were abrasive blasted to the required cleanliness standards. The casing was then pre-machined to accommodate the coating process.
Plasmet HTE was then applied to all internals, 2mm on the casing and 1.5mm of the impeller. Plasmet HTE is a hardwearing, slip-free, three-pack, solvent-free polyamine cured epoxy screed. This coating is resistant to strong concentrations of sulphuric and other acids. It is ideal for areas requiring abrasion (and chemical) resistance. It has been used in cyclones, chemical process vessels, sugar beet pulping drums etc. Plasmet HTE is also useful for building up damaged areas of pump impellers and casings where impact or abrasion are prevalent.
The items were thickness and spark tested to 27Kv and 17KV respectively to check for holidays.
During the refurbishment process, bearing and gasket seals were replaced and the impeller was dynamically balanced. This was all completed before the pump was reassembled for dispatch and re-installation, to ensure the full protection against corrosive seawater.
Our partners in India, Kirloskar Corrocoat Pvt Ltd (KCPL), were asked to protect the internals of a new wet limestone absorber on a coal-fired power plant in Tamil Nadu, in Southern India.
The absorber is a critical part of FGD system at the plant and operates in a highly abrasive and corrosive environment. A system offering both high chemical and erosion resistance was essential to be effective in this environment.
Polyglass PPV (a holding primer) and Polyglass VEF were selected due to its proven ability to offer superior resistance and performance in aggressive conditions.
As the absorber was 41.5 m high it was divided into 4 zones in order to complete the project;
Zone 1: Bottom to 2m shell wall
Zone 2: 2m shell wall up to 19.70m and below spray zone.
Zone 3: 19.70m shell wall up to 30.20m from bottom (spray zone)
Zone 4: 30.2m Shell Wall up to 41.50m from bottom mist eliminator Zone.
Each zone was blasted, ahead of being primed with Polyglass PPV and then coated with Polyglass VEF via spray application, to minimum DFT of 4mm in Zone 1 and Zone 3, and a minimum DFT of 2mm on Zone 2 and Zone 4. The project was completed over 3 months, with a team of 30 men.
Inspection after 6 year’s service;
A KCPL team recently visited the plant to inspect the absorber following 6 years in service. Below are the results:
Zone 1:
Zone 2:
Zone 3:
Zone 4:
No defects were found at any location accessible during the inspection and visually the coating was in excellent condition at the areas which could be observed in inaccessible areas
Conclusion
Following inspection after 6 years in service, the coating was found to be in good condition without loss of thickness, despite the highly aggressive environment, throughout all zones. The team are confident the coating can further sustain another 10 years without any major issues.
We’ve all heard of the term pitting corrosion. But what does this mean and where exactly does it occur? Here we go in to further detail to provide the answers to the questions and also explore ways to repair and protect badly pitted steel.
“Pitting Corrosion” is the formation of holes in an otherwise relatively un-attacked surface. It is a form of localised corrosion that proceeds because of local cell action which produces cavities beginning at the surface. The cavities may or may not become filled with corrosion products. Corrosion products may form “caps” over the pit cavities which are described as “nodules” or “tubercules”. While the shapes of pits vary widely, they are usually rough saucer shaped, conical or hemispherical.
Pitting corrosion is quite common. It can occur on a metal surface because of localised differences in composition or surface contamination, deposition or incorporation of metallic and non-metallic particles, or contact with dissimilar metal. This type of attack can by caused by a break in a protective film on the metal surface, such as an inhibitor film, oxide film or break in coating. It also may be caused by the uneven deposition of solids (metallic salts) which in themselves create a local action because of the potential difference between the salts and metal surface. An example is ferric sulphate.
The Corrocoat Corrofill range consists of fillers for badly pitted steel, in application, which require a high performance, chemically resistant coating system.
One of our specialist corrosion protection coatings would then be applied to complete the process.
A two-pack organic peroxide, catalysed bis phenol ‘A’ polyester filler or grout.
A general-purpose two or three pack epoxy filler, grout and repair compound.
A two-pack, vinyl ester filler and grouting material containing abrasion resistant fillers.
Contact us to find out more on how we can repair and protect corrosion pitted steel and other pieces of equipment or machinery, suffering from other types of corrosion.
Biofoul is our heavy duty, anti-foul coating, developed to provide optimum protection in both sea water and fresh water environments where biofouling and marine growth are evident. Biofoul contains no chemical agents and relies on its performance for a unique blend of metallic copper pigmentation and flakes. It can, therefore be considered non-toxic.
Years ago, mariners coated their wooden vessels with copper sheeting to provide excellent anti-foul properties. Biofoul works in exactly the same way, presenting a copper rich surface to the fouling agents.
Unlike many anti-foul materials, Biofoul forms a hard and durable surface, resistant to scuffing and high velocity water flow. This makes it ideally suitable for use on static constructions as well as pipework and other areas where flow velocity may be a consideration.
One typical area of use is sea water intakes, where marine growth can substantially reduce the inlet size, reducing flow and involving high maintenance levels and cost. Other areas, such as marine piling and support structures, vessel hulls and pontoons also benefit from the long-term protection properties of this product.
The material is a three-pack synthetic, hydrolysable polyester solution designed for application over a corrosion barrier coating – typically Corrocoat’s own Polyglass materials. The product is easily applied using airless spray equipment and has quick dry and curing characteristics.
As an anti-foul, Biofoul provides an excellent alternative to toxic fouling materials, including electrolysis processes, which produce unwanted levels of chlorine which can also cause serious corrosion problems. Biofoul has been tested in an independent laboratory for both effectiveness and non-toxicity.
When first applied, Biofoul is a copper/gold colour. The colour changes with age to the pleasantly green appearance of oxidised copper. This characteristic allows Biofoul to be used not only for anti- fouling purposes, but also for decorative and architectural use on building features such as domes and spires.
View the Biofoul data sheet here.
With a strong working knowledge and expertise in management and engineering, Nigel joined Corrocoat as the Engineering Foreman in 1990. Progressing to the Works Director in 2005, Nigel has made a huge impact and contribution, leading the site operations and engineering team to deliver outstanding results. Nigel has been instrumental in strengthening the engineering team in recent years, encouraging a culture of continuous development and performance improvements, through a number of progressive workplace initiatives. He also works closely with our Pumps Manager, Research and Development division and other areas of the business to ensure the service we offer continues to excel.
Nigel said: “I’d like to take this opportunity to say it has been a privilege to be part of such a fantastic business. I wish the company and the wonderful team, both here in the UK and our partners overseas the very best for the future and have no doubt, the business offering, service and reputation as world leading corrosion specialists will continue to thrive.”
In the lead up to his retirement, Daniel Briggs worked alongside Nigel, in his new role as Works Manager, to ensure a smooth transition in to the duties and responsibilities of managing and overseeing all areas of operations going forward. Daniel has been part of the team here at Corrocoat UK for over 7 years, in technical sales and estimating. He has fantastic working and industry knowledge, and has built and sustained excellent working relationships throughout the company and with clients.
We’d like to take this opportunity to thank Nigel for the past 30+ years – wishing him all the best in his retirement, and also congratulate Dan on his new role.
