For Required Flow Rates Above Standard 5120 or 5000 Series Valves The versatile 5120 Series High Flow Mixing Valve (NSF 61 ASSE 1017) provides the ultimate performance for heating or domestic hot water installations where the required flow rates are beyond the specifications of the standard 5120 or 5000 series mixing valves. The 5120 Series High Flow Mixing Valve allows for domestic hot water storage at temperatures high enough to increase the effective storage capacity of a water heater, kill harmful bacteria and still be delivered at a safe 120°F or less. The valve’s unique design and advanced thermostatic element ensures a stable mixed water temperature throughout the extended 85°-176°F range.