Sometimes, instead of soldering copper water pipes together, homeowners or plumbers use threaded pipe with brass fittings. The brass fittings provide a tight seal and might also contain the shut-off valve, especially on water heaters. Removing fittings when making repairs is normally a quick matter of turning the fitting. However, sediment and age may make brass fittings difficult to loosen. Loosening brass fittings that are stuck requires expanding the connection. Ensure that the water supply to the line is off and the water is purged from the line before disconnecting a brass fitting.
Remove all dirt and debris from around the fitting with a rag. Place a fire-safe cloth on the wall or floor nearest the brass fitting. The fire-safe cloth helps prevent accidental fires when using the propane torch.
Adjust the jaws of the pipe wrench or adjustable wrench to the fitting. This prepares the tool before heating so you do not need to adjust it during the process. Ask a helper to stand nearby with a fire extinguisher in case of accidental fire.
Turn the valve on the hand-held propane torch counter-clockwise until you hear the gas. Light the end of the propane torch with either a striker or wooden match. Turn the valve left or right as necessary until you have a blue cone flame.
Hold the flame over the connection between the fitting and the pipe, with the flame just touching the fitting. Move the flame back and forth over the connection. Holding the flame in one spot will damage the fitting.
Place the pipe wrench or an adjustable wrench over the fitting, once you have heated the fitting for one minute. Turn the fitting counter-clockwise with the wrench. If necessary, heat the fitting for another minute and attempt to turn it until the fitting loosens from the pipe.
Turn the propane torch valve clockwise until the flame goes out. Continue turning the fitting until it is off the pipe.
Heat should be used on smaller brass fittings as well. Always observe safety precautions and remove flammable materials away from the fitting and place a fire-safe cloth over nearby areas.
Never strike a brass fitting with a hammer. This often breaks or bends the fitting, causing the need for full replacement.