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.
The national flag of Sudan consists of three equal horizontal bands of red (top), white, and black (bottom) with a green isosceles triangle based on the hoist side. Sudan Flag - colors meaning/symbolism. Red symbolizes Sudan's struggle for independence and the sacrifices of the country's martyrs. White stands for peace, light, love and optimism. Black represents the people of Sudan ('Sudan' means 'black' in Arabic) Green represents Islam, agriculture and the prosperity of the land.