Also known as Turbo, Tornado or Vortex Flame. A pencil or general purpose flame has a primary and secondary flame, just like a candle. The swirl flame holder acts like a tornado, creating a vortex to mix the primary and secondary flames together. This does two things; it creates a smaller and tighter flame, therefore producing a higher heat concentration on the work piece, and secondly, the gas that is wasted in the secondary flame is now mixed into the primary flame so it more efficiently uses fuel. This flame is good for most applications except when a very low heat intensity is required.