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Bronze Combination Fill Valve and Backflow PreventersSize: 1/2″ (15mm)

Series B911, B911S Bronze Combination Fill Valve and Backflow Preventers is designed for use on the boiler feed lines of commercial and residential hydronic heating systems to provide make-up water to the boiler and prevent backflow when supply pressure falls below system pressure. It consists of a pre-assembled backflow preventer (Watts Model 9D) and a bronze feed water pressure regulator (Watts Model 1156F). This combination high capacity valve provides quick system filling and purging and is easily accessible for servicing.


  • Pre-assembled for ease of installation
  • Series B911 has union NPT x NPT connections
  • Purge lever for manual purging
  • Series B911S has union solder x NPT connections

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Select options below to identify the UPC, Order Code, and Repair Kit for a specific B911

Approval Information

For approval information, please refer to the products specification sheet. For any other information on product certification and documentation information, please visit our certification partner websites: