Following three years of extensive research and development by valve manufacturer Dual Products International, the company has introduced a new range of urethane sleeves, used in its slurry knife gate valves, to the local market.

The introduction is a collaboration between Dual Products and specialist polyurethane product manufacturer Urethane Moulded Products (UMP).

Dual Products produces valves for the mining, sands, steel, power, chemicals and paper industries worldwide, and exports valves to more than 50 countries, while UMP is an established poly- urethane moulding company in South Africa, recognised as one of the largest urethane pipe-lining companies, having supplied over 200 km of urethane-lined pipe since 1980.

UMP director Trevor Carolin points out that the two companies have invested R1.5-million in developing the valves line, which was officially launched in South Africa in April.

“These products are a breakthrough in valve technology and are exclusively available through Dual Products – making it the only company in the world to supply urethane sleeves for the dual slurry knife gate flanges valve. The sleeves have been tested up to a pressure of 40 bar and will be used in the dual high-pressure knife gate valve.”

Dual Products International director Stephen van Rensburg highlights that the products have been tested at Eskom’s Matla power station, in Mpumalanga, and on slurries in different mining applications, including gold and uranium, with positive results.

“Initial urethane versus rubber stroke tests were done in Finland using water to test the effectiveness and durability of the product over other materials. The results showed that a knife gate valve with a urethane sleeve could handle 75 000 strokes, compared with 5 000 using a rubber sleeve. This is one of the main reasons why urethane was selected for the valves,” he explains.

Van Rensburg notes that the use of urethane in these products has opened up the potential for substantial growth, not only in the South African market, but also in Africa and as far afield as North America. “The wear life of the valve and sleeves is one of the biggest selling points. What’s more, improved durability results in savings on maintenance, labour and replacements – factors that are becoming increasingly important in industries across the globe,” he concludes.