Double Flap Valves, also known as Double Flap Valves or Double Flap Gates, are a type of airlock valve commonly used in industrial applications as a component in bulk material handling applications.

Double Dump Valves are primarily used to discharge chunky, pellets, granules or fibrous, bulk materials from hoppers, bins, and cyclones operating under positive or negative pressure.

Double dump valves are used to discharge a flow of material while at the same time serving as an airlock transition point to preserve the pressure differential above and below the valve.

This type of material handling valve is ideal for use with bulky or abrasive materials that would tend to jam or damage a Rotary Feeder

Double dump valves have two trap-door flap plates which open and close on an alternating cycle. The top gate opens to allow collected material to drop through onto the bottom gate. The top gate then re-closes to prevent air leakage above the valve. The bottom gate then opens to allow material to pass completely through the valve. The bottom gate then re-closes to prevent air leakage below the valve. This cycle is continuously repeated in order to maintain a steady discharge of material from the valve, while maintaining a positive seal on the system.

Each flap plate has its own pneumatically operated cylinder and solenoid valve. The timing of the valve is controlled by an electronic signal sent to the solenoid valves. This method of operation is design to provide first class automation with sequential controller for accurate timing of the desire functioning of the valve.