How Hot Does a Propane Torch Heat Copper Pipe?

The maximum flame temperature of a propane torch is around 3600°F (1982°C), which can be used to heat copper pipes for various purposes such as brazing, soldering, or annealing. The heat output of a propane torch can vary, but a common value is around 5.0 BTU/hour.

Propane Torch Flame Temperature

  • Propane has a theoretical flame temperature of around 3,600°F (1,982°C) when burned with pure oxygen.
  • In practical use with air, the flame temperature of a propane torch typically ranges from 2,500°F (1,371°C) to 3,000°F (1,649°C).
  • The actual flame temperature can vary depending on factors such as the torch design, gas pressure, and air-fuel mixture.
  • Higher-end propane torches may have flame temperatures closer to the theoretical maximum of 3,600°F (1,982°C).

Heating Copper Pipes with a Propane Torch

how hot does propane torch heat copper pipe

  • Copper has a melting point of 1,984°F (1,085°C), so the 3,600°F (1,982°C) flame of a propane torch is more than sufficient to heat and melt copper.
  • When heating copper pipes, the goal is to evenly heat the fitting or joint to the appropriate temperature for brazing, soldering, or annealing.
  • Overheating the copper can lead to issues such as poor preparation of the pipe, flux problems, and potential leaks after the joint is completed.
  • It is recommended to practice on a scrap piece of copper pipe before attempting to solder supply lines or other critical plumbing connections.

Comparison to Other Fuel Sources

  • MAP gas (methylacetylene-propadiene propane) has a slightly higher flame temperature than propane, around 3,730°F (2,055°C).
  • Some users prefer propane over MAP gas because the higher temperature of MAP gas can more easily lead to overheating and damaging the copper pipe.
  • Acetylene, which burns at around 4,000°F (2,204°C), can also be used to heat copper pipes. However, acetylene requires a larger tank and hose rig compared to propane or MAP gas.
  • For small-scale copper pipe heating tasks, the higher temperature of acetylene may not provide significant benefits over propane or MAP gas.

Practical Considerations

  • When heating copper pipes with a propane torch, it is important to heat the fitting or joint evenly to avoid localized overheating.
  • Uneven heating can lead to poor preparation of the pipe or paste flux issues, resulting in leaks after soldering.
  • Both propane and MAP gas can be used in upside-down positions, which can be helpful when access is tight or when working in confined spaces.
  • It is recommended to start with a lower flame intensity and gradually increase the heat as needed to avoid damaging the copper pipe.
  • Proper safety precautions should be taken when using a propane torch, including wearing protective equipment and ensuring adequate ventilation.

In summary, propane torches can heat copper pipes up to around 3,600°F (1,982°C), with a heat output of around 5.0 BTU/hour. When heating copper pipes, it is important to heat the fitting or joint evenly and avoid overheating to ensure a successful brazing, soldering, or annealing process. While MAP gas and acetylene can also be used, propane may be the preferred fuel for many small-scale copper pipe heating tasks.