Hammer arrestors are designed to help with water hammer (banging noises) in the water lines when a washer or ice maker are in use. When the appliance’s quick closing valve shuts off, it will exposes any loose piping in the water supply system and make banging sounds. The hammer arrestor helps absorb the shock and minimize or eliminate the banging sound. Oatey manufactures a full line of pipe supports which can assist in securing the loose pipes.