A unidirectional explosion isolation flap valve is an explosion isolation device for dust collector pipelines. It consists of a housing, cover plate, valve disc, counterweight hammer and self-locking device. When gas flows through the air inlet duct, the valve disc opens to allow airflow to pass.

In case of an explosion inside the dust collector and formation of an explosive gas cloud, the valve disc is acted upon by the reverse gas flow and closes automatically to isolate gas circulation. The self-locking device engages immediately, separating the production area from the dust collector and preventing the explosion from propagating to upstream pipelines and equipment, so as to safeguard personnel and property safety.

Unidirectional explosion isolation valves are normally installed horizontally, at a position 2~7 meters from the air inlet of the dust collector.

The opening angle of the valve is approximately 89°. It opens and closes automatically with changes in wind speed. When the fan stops, the valve closes automatically, sealing the dust collector into a closed space and preventing sparks, embers and sundries from entering the dust collector.