What is the Difference Between Acetylene and Propane?

The main differences between acetylene and propane as fuel gases for welding and cutting are their flame temperature, oxygen consumption, and safety aspects. Here are the key differences:

• Flame Temperature: Acetylene has a higher flame temperature when burning in oxygen (3100°C) compared to propane (2800°C). This makes acetylene more suitable for cutting applications.
• Oxygen Consumption: The stoichiometric oxygen requirement for acetylene is 1.2 to 1, while for propane, it is 4.3 to 1. This means that more oxygen is consumed when using propane, which can affect the economy of the welding process.
• Safety: Acetylene is lighter than air and will rise if leaked, while propane is heavier than air and can accumulate at lower levels. Acetylene has a lower ignition range (2.5% to 82%) compared to propane (2.1% to 9.5%). Some people argue that propane is safer than acetylene due to its wider ignition range, but both gases are flammable and should be handled with care.

In summary, acetylene is generally considered better for cutting applications due to its higher flame temperature and lower oxygen consumption. However, propane can be used for cutting and welding as well, especially when acetylene is not available or when the higher flame temperature of acetylene is not required. Both gases have their advantages and disadvantages, and the choice between them depends on the specific needs of the welding or cutting task at hand.

Comparative Table: Acetylene vs Propane

Here is a table comparing the differences between acetylene and propane:

Acetylene is hotter than propane, with a temperature of 5,800°F, while propane has a temperature of 5,100°F. Acetylene preheats faster and can be used for welding, while propane is not suitable for welding. Acetylene is more expensive and less stable than propane, which is less expensive and more stable. When cutting with acetylene, a single-piece tip is required, while propane requires a T-hose and specially designed torch tips. Acetylene can cut through thicker materials, while propane is more suitable for cutting thinner materials. The cost and efficiency of acetylene cutting are higher than propane cutting, making propane a more cost-effective option. The flame in an acetylene torch is more reducing than the flame in a propane torch.