ISO/TS 27469:2010 specifies a method for determining the following:ability of fire dampers installed in ventilation systems to prevent the spread of fire and heat through designated fire divisions; typical ratings are given in ISO 13702:1999, Table C.5.fire damper operational reliability in the petroleum, petrochemical and natural gas industries, particularly offshore installations;ability of fire dampers installed in ventilation systems to withstand blast overpressures that may result from the explosion of a flammable gas.ISO/TS 27469:2010 applies to different start-up operations for different types of furnace and, therefore, tolerances in test conditions