Seeking to cut product waste and improve efficiency, Tarmac’s Ballidon site, which includes three limestone quarries, chose Rota Val heavy-duty HD450 rotary valves to control high levels of discharge of limestone powders and granules. In order to follow through on a policy to control environmental impact, and to minimize the release of crushed limestone powder, Rota Val recommended five new HDG rotary valves. The two silos fitted with Rota Val rotary valves already load the conveyors correctly. The HD heavy-duty valves are available in 12 standard valve sizes ranging from 50 to 750mm to give capacities up 250m3/h, and can be made in round, rectangular or square-flange options. The valves may be manufactured as standard in cast iron, SG iron, aluminium and stainless steel, with alternative materials such as Monel, Inconel, Titanium and Hastelloy also available. The HD series of valves may be supplied for temperature ranges from -100 to +900C.
