The sliding vane compressor is a rotary type compressor, meaning a rotating device is used to compress gas. Vanes on the rotor trap gas between the rotor and cylinder walls. This gas is compressed and released into the discharge line. The sliding vane compressor consists of a rotor mounted off-center in a cylinder slightly larger than the rotor. The rotor has a series of radial slots that hold vanes. These vanes are free to move in and out of the slots, but always maintain contact with the cylinder wall.