Flame Propagation Posted on 11th November 201529th August 2020 by ThePD (The Project Definition) Flame Propagation is the movement of a flame that is the spread of a flame in a combustible environment outward. Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window) Related Posted in Engineering and tagged fire, flame, safety. ThePD (The Project Definition) ThePD has been developing the Preferred Project Definitions based on the actual project execution and operation experiences and knowledge with the Project Language, and sharing with you daily basis.