== EGR vacuum switching valve == Despite the rather lengthy name the EGR-VSV (exhaust gas recirculation vacuum switching valve) does little more than allow vacuum to flow through the system depending on engine coolant temperature.
A double bond in chemistry is a chemical bond between two chemical elements involving four bonding electrons instead of the usual two. The most common double bond, that is between two carbon atoms, can be found in alkenes. Many types of double bonds exist between two different elements. For example, in a carbonyl group with a carbon atom and an oxygen atom. Other common double bonds are found in azo compounds (N=N), imines (C=N) and sulfoxides (S=O).
In fact, the carbon atoms in the single bond need not be of the same hybridisation. Carbon atoms can also form double bonds in compounds called alkenes or triple bonds in compounds called alkynes. A double bond is formed with an sp 2 hybridized orbital and a p-orbital that isn't involved in the hybridization.A triple bond is formed with an sp hybridized orbital and two p-orbitals from each atom.n fact, the carbon atoms in the single bond need not be of the same hybridisation. Carbon atoms can also form double bonds in compounds called alkenes or triple bonds in compounds called alkynes. A double bond is formed with an sp 2 hybridized orbital and a p-orbital that isn't involved in the hybridization.