Pre-Heat Burner SystemsPropane Pre-Heating of Steel

Smithweld pre-heat burners, offer a low-cost, reliable & efficient method for preheating by using the FREE oxygen in the atmosphere. The burners have specially designed clamps to allow mounting in various applications without the need to hold the torch.

There are generally 3 methods of flame heating available on the market that allow us to bring the temperature of steel up to an acceptable level prior to welding. The degree of preheat generally depends on:

  • the total steel chemistry such as percentage of carbon or carbon equivalent
  • material thickness
  • joint restraint
  • environment (humidity/ ambient temp)
  • Procedure involved

When the need for preheating has been established, the next decision is to choose the best and most economical method.
The three most common methods of heating are:

  • oxy/acetylene
  • oxy/propane
  • straight propane

The first two methods, though effective are the more expensive and not always the best, as they require an operator to hold and apply the heat and still use two types of compressed fuel.

Preheating of steel should be conducted in such a way that hot spots or localized heating should be avoided. A more general or diffuse heating method, using straight propane should be the first choice to prevent damage to the steel or casting.