The purpose of an air gap is not really to allow air to escape but rather to keep dirty water from back flowing into the DW. An autovent allows air into the system to allow for proper drainage and an air gap is not dependant on one or vice versa. The autovent takes the place of a vent stack to the roof.
Sudan is a member of the United Nations, the African Union, the Arab League, the Organisation of Islamic Cooperation and the Non-Aligned Movement, as well as an observer in the World Trade Organization. Its capital is Khartoum, the political, cultural and commercial centre of the nation.
Sudan is in Africa, south of Egypt. It shares borders with Egypt, Libya, Chad, the Central African Republic, the Democratic Republic of the Congo, Uganda, Kenya, and Ethiopia. It is the largest country in Africa and the ninth largest in the world, covering one million square miles (2.59 million square kilometers).