The
mixture of
gases used for a
variety of
metalworking practices, most commonly
welding,
cutting and
brazing. By varying the
precise proportion of the mix
flames of different
temperatures and
qualities can be obtained, which allows different
metals to be worked on and different
results to be obtained.
The most common proportion is an exact 50:50 mix of oxygen and acetylene which results in what's known as a neutral flame which has an intense blue colour, becoming almost white at the centre. This central portion of the flame is burning at around 5,500 degrees Centigrade which is perfect for cutting and joining most steels.
The oxygen and acetylene gases are usually stored in pressurised cylinders. The oxygen tends to be at pressures approaching 2,000 psi (which means it's liquid at standard room temperature), whereas acetylene becomes dangerously unstable at any pressure above 15 psi. It's obviously of vital importance for the torch operator to be aware of this difference in pressure otherwise some extremely nasty accidents can occur.