Abstract: A method and system is disclosed for adding chlorine to a water supply system to kill bacteria, and in particular, Legionella bacteria. A corrosion inhibitor additive is added with the chlorine, to ensure that corrosion or other damage to the pipes does not occur. A method is disclosed for initially setting up proper levels of chlorine and corrosion inhibitor, and maintaining those levels. Systems for adding the materials to the hot water supply system are disclosed to ensure that they are adequately and thoroughly mixed into the water.

Abstract: A method and an apparatus are disclosed for cleaning water pipe. The pipe is preferably connected to a source of water which normally flows through the pipe to an outlet. A valve is positioned at the outlet and is rapidly opened and closed. When the valve is closed a pressure pulse is created in the pipe and travels towards the source of fluid. This wave is reflected back from the source towards the outlet. The alternate waves expand and contract the pipe wall, and cause pressure fluctuations within the pipe. The combined action removes scale from the wall of the pipe, and when the valve is opened the removed scale passes out of the pipe.