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 name comes from the name for the band of savannah land in Africa along 12Â°N Â± 4Â°. The Arabic name for this geographic band was bilad as sudan, which means literally land of blacks. The Republic of Sudan is of course only part of the geographic region of the sudan. The geography of Sudan is largely plateaus with mountains in the south and to the west (Jabal Marrah) along with mountains along the Red Sea coast (the Red Sea Hills). The economy is dominated by the river valleys of the Nile Rivers, White and Blue, and their tributaries.