Valves increase productive life
European Gate Valves Ltd (EGV) have supplied double-flap gate valves for use in coating plants on a number of contracts. The valves have overcome premature wear and performance problems that have affected rotary valves previously fitted and have extended valve operating life on asphalt plants from an average of only two months to in excess of two years.
The valves are fitted on pneumatic conveying systems that carry filler fines from a bag filter to a storage silo. Despite rotary valves being specified as abrasion resistant, they have still lost performance within a few weeks. The abrasive action of the conveyed material on the casing, combined with the wiping action of rotary valves, increases clearance between the rotor and casing. This enlarges leak paths available to the conveying air, bypassing the rotor and compromising performance.
The EGV double-flap valves are said to eliminate the continuous process of maintenance/replacement/repair as sealing is achieved through the mating of two flat-ground surfaces. No rubbing or wiping action is involved, which minimizes the potential for moving-parts wear. Replacement of any wear parts can be carried out through access covers, without the valve being disconnected or removed from the process line.
