WATTS® 0061935 9D M3 Backflow Preventer, 1/2 in Nominal, Union FNPT x Union Joint End Style, Forged Brass Body, Dual Check, Domestic

WA9DG MFG #: 61935
  • Backflow Type: Dual Check
  • Country of Origin: US
  • Dimensions: 4-15/16 in W x 2-9/16 in H
  • Domestic/Import: Domestic
  • End Style: Union FNPT x Union Joint
  • Manufacturer Name: Watts Water Technologies
  • Media: Water
  • Nominal Size: 1/2 in
  • Series: 9D M3, 9D Series
Series 9D is specially made for smaller supply lines and ideally suited for laboratory equipment, processing tanks, sterilizers, dairy equipment and similar applications. It is particularly recommended for boiler feed lines to prevent backflow when supply pressure falls below system pressure. Series 9D is suitable for use on hot or cold water and can be used under continuous pressure. It features a primary check valve utilizing a rubber disc seating against a mating rubber part to ensure tight closing. A secondary check valve utilizes a rubber disc-to-metal seating. In the event of fouling of the downstream check valve, leakage would be vented to atmosphere through the vent port thereby safeguarding the potable water system. Construction is brass body with stainless steel working parts, integral strainer and durable rubber discs. Female union inlet and outlet connections. Sizes 1/2 in and 3/4 in. Drain is 1/2 in thread connection.
  • Features and More


  • True line-sized construction allows the check modules to open further allowing dirt and debris to pass more freely reducing check fouling
  • Stainless steel internal parts
  • Maximum flow at low pressure drop
  • Furnished with union connections to facilitate removal and replacement for maintenance
  • Compact for economy combined with performance
  • Design simplicity for easy maintenance
  • Can be installed vertically or horizontally
  • Durable, tight seating rubber check valve assemblies


  • For non-health hazard applications in smaller supply lines
  • such as laboratory equipment
  • processing tanks
  • sterilizers
  • dairy equipment
  • and specifically for boiler feed lines


  • ASSE 1012
  • CSA B64
  • PROP65: This product can expose you to chemicals including lead which is known to the State of California to cause cancer and birth defects or other reproductive harm.


  • Limited