Switching from cast iron to copper piping for residential hot water can be done by the home handy-person. Copper piping retains heat and resists corrosion much better than cast iron. Follow these steps to replace cast iron piping with copper.
Step 1: Cut Copper Pipe to Size
Clamp the copper pipe with friction clamps so 6 inches protrudes. Cut the copper pipe sections to the sizes you need.
Step 2: Weld the Copper Pipe at Joints
Determine where right-angled joints are needed. Cut pieces of copper pipe to make the joints and weld these pieces on with the acetylene torch.
Step 3: Thread the Copper Pipe Fittings
Use the threading dies to thread the copper pipe at section ends to make the fittings.
Step 4: Ream the Pipes
Use the reamer to remove all metal burrs at the cut pipe ends before adding couplings. Attach the brass couplings at the threaded fittings to join pipe sections
Step 5: Remove the Cast Iron Pipe
Use the standard pipe wrench to release the cast iron pipe couplings and remove the pipe. Replace the cast iron pipe with your prepared copper piping.