Steel pipe manufacturer Hall Longmore is looking to attract a key domestic market segment with its newly launched dual layer fusion bonded epoxy (FBE) coatings.

MD Kennith van Rooyen tells Engineering News the company, which is based in Wadeville, Gauteng, recently commissioned a dual spray booth to undertake the FBE coatings, which include abrasion-resistant coatings and moisture-resistant overlays.

Since the automated machine installation, the company has upgraded the system to operate at higher speeds, with the current operational speed being about 3 m a minute, which is “fairly quick as far as coating is concerned”, he states.

“We brought this technology to South Africa because we believe there is a market segment for steel pipes between 100 mm and 600 mm where quick application of high-quality materials will provide in excess of 50 to 70 years of infrastructure lifespan in terms of corrosion resistance,” says Van Rooyen.

Both the abrasion-resistant overlay and FBE powders are applied with a positive charge of the powder and a negative charge on the pipe, applied in separate booths about 1 m apart in a continuous production line. Before the application, pipes are shotblasted, induction heated, brushed and high-pressure cleaned. Following their spraying, the pipes are immediately quenched to cure the coatings.

Van Rooyen says FBE pipes could have a specific niche in the water industry, but are also well suited to the abrasive and corrosive oil and gas industry. “Looking at the international oil and gas sector, especially the Americans and Europeans, they love this coating because it is so robust.”

The moisture-resistant overlay is specifically suited for applications in marshy and bushveld areas with a lot of moisture, he points out.

Hall Longmore was able to reduce the cost of FBE coating application by using an automated process, but the powders themselves are still costly.

However, Van Rooyen adds that the local supplier of the powders has shown an interest in manufacturing them locally if demand proves strong.

If the production line is fully manned, as many as 120 12 m pipes can be FBE-coated during an eight-hour shift.