Step 5 · Clean and Prepare Pipe
Once the old fittings are off, inspect the end of the copper pipe. It must be clean, smooth, and perfectly round for the new valve to seal. Use some emery cloth or fine-grit sandpaper to clean off any corrosion, old plumber's putty, or burrs from the last inch of the pipe. Wipe it clean with a dry rag to remove any dust or debris. The surface where the new ferrule will sit must be pristine.