The double dump valve — also known as a double flap valve or trickle valve — provides dust-tight, pressure-sealed material discharge from hoppers and receivers without mechanical feeder complexity. Two counterweighted or spring-loaded flap valves operate in sequence — the upper flap opens to admit a batch of material, closes to seal, then the lower flap opens to discharge — maintaining a continuous pressure seal throughout.

With no rotating parts and no drive motor, the double dump valve is inherently low-maintenance — suited to continuous-duty applications in dusty, high-temperature, or chemically aggressive environments where motor-driven feeders require frequent attention. The counterweight or spring loading is set to the operating pressure differential, ensuring the valve remains closed against system pressure during normal operation.

Used extensively in bag filter hopper discharge, cyclone underflow discharge, and gravity feed into low-pressure conveying lines. Available in cast iron, mild steel, and stainless steel construction for different material and temperature service.

Key Applications: Bag filter hopper discharge · Cyclone underflow · Low-pressure gravity feed

Materials: Dust · Fine powder · Granules · Collected filter cake