Biological contactor for treatment of sewage and drainage water; Hot water heaters; Tankless water heaters; Waste water purification apparatus, installations and tanks; Water filtering apparatus; Water heaters; Water purification installations; Water purification, sedimentation and filtration apparatus for clarification, thickening and filtration of water, waste water and industrial water; Water softening units; Water treatment apparatus, namely, clarification and thickening machines for use in treatment of liquids in the nature of water, waste water and industrial water; Water treatment equipment, namely, cartridge filtration units; Water treatment equipment, namely, chemical sterilization units; Water treatment equipment, namely, reverse osmosis filtration units; Water treatment equipment, namely, ultraviolet sterilization units; Water treatment equipment, namely, water filtration units