Series PB56 Purge and Balancing Valves are used in heating applications on boiler return piping to facilitate removal of air from heating zones on initial fill and to control water flow through circulation loop. It also serves as a shutoff valve and a drain valve for each zone or loop. It consists of a bronze body construction with inlet x outlet solder connections, male hose thread connection for blow-off, and balancing adjustment. It is a self-contained, tight seating ball valve and is ideal for pipelines that require exceptionally high capacity purging. Maximum Working Pressure: 50psi (344.8kPa).