Question 1529 Deck General

The correct answer is B) dissipating the heat of an external flame. Flame screens on tank vents are designed to prevent explosions by dissipating the heat of any external flame, thereby preventing the flame from entering the tank and igniting the combustible gases inside. The small openings in the flame screen act as a heat sink, absorbing and dispersing the heat of the flame before it can pass through and reach the tank's interior. This effectively blocks the propagation of the flame and prevents an explosion from occurring. The other answer choices are incorrect because they do not accurately describe the primary function of the flame screen. Allowing the escape of flammable vapors (A), preventing flammable vapors from entering the tank (C), and absorbing flammable vapors (D) are not the main purposes of the flame screen, which is to stop the transmission of an external flame into the tank.