Soldering Copper Pipe with Ball Valves Video
If your remodeling job requires that a water pipe be shut off or relocated, don't just cap it off. Solder a ball valve into the line. This will allow you shut the water off and reconnect the sink easily without having to shut off all the water. You will have to remove a short section of the copper pipe to make room for the valve. This is normally about 1-1/4".
Cut the pipe, clean both ends and the inside of the fitting, flux it and solder it in place. Then you will be ready to keep moving forward on the kitchen remodeling project.
Once the pipe is cool to touch, take a rag or a paper towel and wipe the area soldered to get all the flux off. If you don't, the flux will corrode the copper pipe over time and cause a leak.