The F739 Series Ductile Iron fixed orifice manual balancing valve is complete with integral pressure temperature ports and memory stop. Special calculators or meters are not required to set the F739. Direct system readings are taken across the orifice. Depending on size, the F739 Series provides between 2880 to 6480 -degrees of throttling adjustment, resulting in precise setting of system flow. The F739 is also capable of providing system isolation for maintenance. The integral memory stop feature allows the system to be returned to its retained settings once maintenance is completed. The NIBCO® manual balancing valves provide the ultimate solution for a wide range of mechanical and HVAC chilled and hot water application requirements to ensure a balanced system and a comfortable indoor climate. NIBCO® valves and components are also backed by the NIBCO 5-year 125% limited warranty.