The VacuRester™ is designed to prevent pressure spikes caused by cavitation by temporarily breaking the vacuum that can be pulled just beyond the closing valve. The VacuRester operates with a much lower air charge, and the piston starts high in the barrel and travels down - functionally the opposite of a traditional water hammer arrester. When installed directly after the valve, the VacuRester will allow a more gradual stop of the water flow, to prevent cavitation in high-flow, long-run plumbing systems.