Step 6 · Clean and Prepare the Pipe
Once the old valve is off, thoroughly inspect the end of the copper pipe. Use a rag to wipe away any old plumber's putty, dope, or debris. Take a piece of emery cloth and gently sand the last inch of the pipe where the new compression ring and nut will sit. The goal is to create a clean, smooth, and slightly scuffed surface for the new components to seal against.