Manual Pressure Relief Doors

Model PP-10 (positive) and model PN-10 (negative) pressure relief doors are designed to open automatically 1w.g. above normal operating system pressure. The function of these doors is to prevent ductwork form imploding or exploding in the event dampers close while the fan is still operating. These doors permit rapid neutralization of the pressure differential between the inside and outside of the HVAC system. The pressure relief setting of the door can be factory adjusted from 1"w.g. to 12"w.g."