Siphons are used for draining water from the fittings into the internal waste-water system. The products meet the requirements of the EN 274 Standard; the used materials are heat-resistant to 95°C and they are resistant to the effects of all media commonly found in domestic waste waters, including waters containing fat and various chemicals. A water disconnecting trap is used in siphons to prevent infi ltration of odours from the waste pipe. Regular cleaning and the application of ventilating heads contribute to proper function and fast water drainage. The fl ow capacity is substantially infl uenced by the layout of the waste system and particularly by the waste pipeline gradient.