Smith Equipment has provided a two-part series on how to cut with acetylene and alternative fuels with detailed safety and set up instructions. These videos are the perfect place to begin if you’re new to oxy-cutting or if you need a refresher on torch and fuel set up and safety.
The following video demonstrates the proper way to set up, cut, and shut down an oxy-propane cutting system. The same rules apply to cutting with propylene.
The Basics of Cutting with Propane as an Alternative to Acetylene:
Here are some key points to keep in mind from the video, along with some additional information:
Safety Concerns When Cutting with Alternative Fuels
- Make sure the tanks are safely secured.
- Open the valve to the oxygen before attaching a regulator in order to blow out any debris before attaching the regulator with a wrench. Shut off the oxygen valve until you are ready to cut.
- Add flash back arrestors between the hose and the torch.
- Use a propane cutting tip.
- Perform a leak check for all of the connections and fuel lines.
- Wear proper shading glasses or a full face shield.
- Wear leather gloves.
Testing Gas Flow for Alternative Fuels
Cutting is performed with a neutral flame that has the correct balance of oxygen and fuel gas. The way to test your flame is by placing it about an inch above a metal surface so that the flame creates a star pattern on the metal. The ideal flame will be sharply defined and its legs will not spread out further than 3 inches.
If the flame is oxidizing, the star pattern will be extremely sharp and its legs will be much shorter than the star pattern of a neutral flame. An oxidizing flame will not produce enough heat and will cause foam and sparks on the metal. This is the result of having too much oxygen mixing with the cutting fuel.
A carburizing flame will have fuzzy legs that aren’t sharply defined and they will be much longer than three inches. This will produce too much heat and will boil the metal as it’s being cut. This is the result of having too little oxygen mixing with the cutting fuel.
Cutting with Alternative Fuels
- Hold the torch about a half inch above the work piece.
- Keep in mind that alternative fuels concentrate their heat on the outside of the flame.
- Heat the metal until it is colored orange—the sign that it is properly pre-heated and ready for cutting.
- When done cutting, turn off the oxygen valve and then the fuel valve.
- After shutting down the oxygen cylinder and then the propane cylinder, drain the torch system of all gases.