Selection of Cone or Flap depends on the characteristics of material to be handled and system requirement like pressure sealing. Cone valve has a better sealing than the flap valve. However, in smaller size valves, the cone can act as an obstruction in the flow resulting in clogging of the small opening. The cone valves usually have round opening whereas the flap valves can have square. Double Flap/Cone Valves are used for extracting bulk material from collection vessels which are maintained at a pressure different than the outside. Typical locations include below ESP hoppers & Bag House hoppers etc., where the dust collection chambers are at a negative pressure. The valves can handle fine dusty or grainy material like cement, crushed ore, sugar, minerals, grains, plastics, dust, fly ash, flour, gypsum, lime, coffee, cereals, pharmaceuticals etc
