equipment for use in hot water heating systems, namely, hot water tanks, accumulator tanks and expansion tanks; water storage tanks and connectors therefor, namely, stainless steel, sold as a unit; pressurized diaphragm-type storage tanks and system-components for well water systems; commercial and residential indirect fired hot water heaters and hydronic systems and components, namely, a pressurized, sealed-in air cushion expansion tank and air elimination equipment to provide oxygen-free, hydraulically stable hydronic system operation, namely, a hydronic heating expansion tank, an air purger, in residential systems, an air vent, and in commercial systems, an air eliminator valve and an air separator; water treatment equipment for domestic and commercial applications, namely, strainers for water lines, pressurized and unpressurized water supply tanks for water supply use, pressure booster system tanks, filters, water softening units, reverse osmosis water processing units, namely, ion exchange resin processing units for water, ultra-violet water filtering units, and replacement parts therefor