A plug door is a door designed to seal itself by taking advantage of pressure difference on its two sides and is typically used on aircraft with cabin pressurization. The higher pressure on one side forces the wedge-shaped door into its socket, making a good seal and preventing it being opened until the pressure is released.
Non-plug doors rely on the strength of the locking mechanism to keep the door shut whereas a plug door relies on the pressure differential to keep it shut.
The term "plug door" may also refer to a sliding bus door that is not actually held in place by pressure, but is mechanically wedged into place when closed.
Read more about Plug Door: Pressure-sealed Plug Doors, Other Plug Doors
Famous quotes containing the word door:
“It’s true, as Marya Mannes says: “No one believes [a woman’s] time to be sacred. A man at his desk in a room with a closed door is a man at work. A woman at a desk in any room is available.””
—Lillian Breslow Rubin (20th century)