Backflow seals; Apparatus for the distribution of water; Apparatus for the supply of water for sanitary purposes; Apparatus for water supply; Installations for the control of water pollution; Installations for the distribution of water; Safety fittings for water pipes; Safety valves for water apparatus; Safety valves for water pipes; Stop cocks being safety apparatus for water apparatus; Stop cocks being safety apparatus for water pipes; Stop cocks for regulating water; Stop valves being safety apparatus for water apparatus; Stop valves being safety apparatus for water pipes; Water pipes for sanitary installations (parts of); Water-pipes for sanitary installations