Apollo 4ALF-100 Series double check valves are used in water supply systems to prevent backflow and contamination. They ensure the safe and reliable flow of potable water by preventing the reverse flow of contaminated water, safeguarding public health and water quality. These double check valves have lead-free bronze construction for enhanced safety in potable water systems, meeting regulatory standards and protecting public health. They feature a FNPT connection that offers compatibility with standard pipe fittings, simplifying installation and allowing for easy integration into existing plumbing systems. These 4ALF-100 Series valves can operate at temperatures ranging from - 33 to 180 degrees F.