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Bronze boiler feed valve with NPT union connection, 8 1/2 inches long, 5 1/4 inches high

Watts

Watts B911-M3 Boiler Feed Valve 1/2 in 10-25 psi 100 psi 212°F

SKU CH-WG77-H4JNB

A boiler feed valve with backflow prevention, adjustable from 10 to 25 psi and rated for 100 psi at 212 °F

  • TypeOther
  • Adjustable pressure range 10 to 25 psi for precise system control
  • Maximum operating pressure 100 psi handles demanding boiler applications
  • Withstands fluid temperatures up to 212 °F for reliable hot-water service
  • Bronze body construction resists corrosion and extends valve life
  • ASSE 1012 certified backflow prevention protects potable water supply

Boiler Feed Valve 1/2 in

The Watts B911-M3 is a boiler feed valve with integrated backflow prevention designed for hydronic heating systems. It connects via a 1/2 inch FNPT and NPT union to automatically maintain system pressure. This component suits installers and maintenance professionals working on residential or light commercial boilers. It arrives new and meets ASSE 1012 standards for backflow prevention.

Pressure Range and Connection Limits

The valve adjusts system pressure between 10 and 25 psi and withstands a maximum pressure of 100 psi. Its bronze body handles fluid temperatures up to 212 degrees Fahrenheit. The fixed 1/2 inch connection size and FNPT union configuration determine piping compatibility. Installers must verify that the system operating pressure stays within the adjustment range and does not exceed the maximum rating.

Capacity and Operational Headroom

The valve comfortably handles typical boiler fill requirements within the 10 to 25 psi adjustment window. It runs out of headroom when system demand pushes pressure toward the 100 psi maximum or when fluid temperatures approach the 212 degree Fahrenheit limit. The unit is not suited for high-pressure steam systems or applications requiring larger pipe diameters. California Proposition 65 warnings apply regarding chemical content.

Highlights

  • Adjustable pressure range 10 to 25 psi for precise system control
  • Maximum operating pressure 100 psi handles demanding boiler applications
  • Withstands fluid temperatures up to 212 °F for reliable hot-water service
  • Bronze body construction resists corrosion and extends valve life
  • ASSE 1012 certified backflow prevention protects potable water supply

Specifications

BrandWATTS
TypeOther

Questions about this item

Should I choose the 10-25 psi adjustment range or a different pressure setting for my boiler?

The valve adjusts from 10 to 25 psi so you can match the boiler's required fill pressure within that window.

What does the 100 psi maximum pressure mean once the valve is installed?

It is the highest supply pressure the valve can withstand without damage; normal operation stays well below that limit.

Does the ASSE 1012 standard cap the valve's performance in any way?

ASSE 1012 certifies the backflow prevention function; it does not restrict the 10-25 psi adjustment range or the 100 psi pressure rating.

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