This Technical Specification 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; NOTE It is planned to determine the methodology during the testing and development phase. ability of fire dampers installed in ventilation systems to withstand blast overpressures that may result from the explosion of a flammable gas. This Technical Specification applies to different start-up operations for different types of furnace and, therefore, tolerances in test conditions at the beginning of the test are not described in detail. The fire test enables only a limited assessment of the actuating mechanism being carried out and additional tests can be necessary to fully evaluate its operational reliability.