11 Sewage clarification systems and devices, namely, sewage treatment plants; systems and devices for water supply, water distribution and water conduit, namely, metered valves; water filtering devices, namely, water filtering units for industrial use in particular for the use in vehicle washing apparatus and water filters; parts for the aforementioned systems all sold as a unit, namely, metered valves, pumps for water supply systems, water conduits, namely, tubes and pipes, accouterments, namely, cocks and valves, mixing batteries for water conduits, water containers and service water containers not made of metal and not made of brick work, namely, tanks for water purification instillations; filter containers, namely, water coolers, water filters containing sand, multilayer water filters, accouterments for inlet and outlet, in the nature of accessories for controlling the inflow and outflow of liquids, namely, valves, water meters, water tubes, water cocks, water faucets; water faucet aerators, disinfection and sterilization apparatus for sewage systems, namely, sewage treatment plants * the aforesaid goods only in the field of waste water treatment installations for commercial vehicle washing *