911, 911S Combination Fill Valve and Backflow Preventer
Series 911, 911S Combination Fill Valve and Backflow Preventers are for use in 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 brass Watts Model 9D backflow preventer and a bronze Watts Model 1156F feed water pressure regulator in one pre-assembled unit. Model 911 has union NPT x NPT connections. Model 911S has union solder x NPT connections. The Series 911, 911S has a high capacity fill valve that provides quick system filling and purging. It is designed for use in the boiler feed lines of hydronic heating systems.
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Technical Data
Available Materials:
Cast Iron
Pressure Rating:
to 100 psi
Available Sizes:
1/2in
Connection Types:
Solder, Threaded
Thread Types:
NPT
See product datasheet for additional details