The 3M Aqua-Pure Whole House Scale Inhibition Inline Water System AP430SS is designed to help reduce scale build-up and corrosion - thereby helping to extend the life on hot water-using appliances such as water heaters (standard (gas or electric) and tank-less), boilers, clothes washers and dishwashing machines, and on plumbing fixtures like faucets, pipes, and shower heads. The AP430SS provides flow of up to 10 GPM with ¾” NPT inlet/outlet connections.Scale is calcium and magnesium deposits that often form when hard water is heated. Water hardness is responsible for most scale formation in pipes, water heaters, finishes and flat surfaces, and other water using appliances. Over time scale build-up can significantly shorten the life of any water-using appliance. Also scale buildup inside pipes causes loss of water pressure as the interior gets smaller and smaller over time. The AP430SS contains polyphosphates to bind calcium and magnesium hardness minerals, helping to prevent them from precipitating out (or becoming a solid) and building up on metallic surfaces. Polyphosphates also helps prevent corrosion by forming a thin protective layer on the metal surface. The 3M Scale Inhibition Water System AP430SS is tested by NSF International to NSF/ANSI Std. 42 for material and structural requirements only.The overall single vessel/cartridge design of the AP430SS makes the 3M Aqua-Pure AP431 Water Filter Cartridge change-out easy for professionals as well as end users. Change disposable filter cartridge every 6 months or sooner if you observe noticeable reduction in water flow rate. The AP430SS is to be installed on the cold water supply line of the water heater or at point-of-entry of water into the home. Tools and parts required (not included): one ¾” stop and waste valve (compression type), PTFE tape, two ¾” male x ¾” street adapters, one ¾” compression gate valve, and pipe cutter. Read all instructions carefully before attempting to start installation. The existing shut-off valve remains in place and still acts as the cold water shut-off. This filter system has 3/4” connections. The AP430SS can be adapted to various pipe sizes by using reducing adapter on either end. Installation fittings can be sweated or threaded. Use galvanized fittings for installation on galvanized pipe.