This 4 inch lead free double check valve backflow preventer assembly is designed to prevent the reverse flow of contaminated water of non-potable quality from being pumped or siphoned into the potable water supply due to backsiphonage and or backpressure. It is ideal for protection at cross-connections identified as non-health hazard applications and from other contaminants found at the service line entrance. This assembly consists of an fused epoxy coated cast iron body using ArmorTek(TM) coating technology for advanced corrosion resistance construction, outside stem and yoke resilient seated gate valves, test cocks, and a modular check design for easy maintenance with center stem guide. The captured spring is accessible through a bolted cover plate. The coating on this backflow assembly uses ArmorTek technology to resist corrosion due to microbial induced corrosion (MIC) or exposed metal substrate.