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The AVDO self-acting constant flow controls are used to maintain a minimum flow rate (e.g. through a low water content gas boiler) or to control differential pressure in a heating system. The closing of radiator or zone valves due to reduced heating demand may result in low flow and increased system differential pressure (potentially dead heating pumps). AVDO valves open with a falling system load and allow flow through a bypass line whenever the differential pressure through the valve exceeds set point; ensuring a minimum flow rate or a system differential pressure at minimum system load.

  • Opens on rising differential pressure
  • Operates without impulse tubes
  • Can be supplied with NPT or solder tail pieces
  • Connection: Union Solder
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    Manuals (1)


    Connection Type:

    C x C

    Max Pressure (PSI):


    Valve Type:



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