Fire sleeves help to prevent the spread of fire where plastic ductwork penetrate fire compartment walls.
They consist of a continuous pressed steel shell containing a high performance graphite based intumescent material which reacts under the influence of heat to exert pressure on the plastic vent duct as it softens to form a carbonaceous char which provides an effective insulation plug thus preventing fire passing through to the adjoining compartment.
They should be used where a plastic duct penetrates a fire rated wall.
