Exit only water combination air valve" "Mod. FOX 3F - EO

The air valve will ensure the proper  operation of the pipeline  network  allowing the release of the air pockets during  working  conditions and  the  evacuation  of  large  volumes of  air  during  filling operations.


Construction and  advantages

  • Body in ductile cast  iron  provided  with internal ribs for consistent and accurate assembly guiding, NP 40.
  • Supplied with fixed  or mobile flanges drilled according to ISO standard ( other drillings on request) NP 10/16/25/40.
  • Drainage valve for chamber control and draining.
  • Mobile  block group formed by a full polypropylene cylindrical float (**) and an upper disk in polypropylene.
  • Nozzle  and gasket  holder  (pat. pending) wear resistant thanks to gasket compression control.
  • Maintenance can be easily performed from the top without removing  the air valve from the pipe.
  • Mesh and cap in stainless steel

Operating principle

During  pipe filling it is necessary to discharge as much air as water flows in.  FOX 3F-EO will make sure  to perform this task allowing the release during working conditions. During operation, an air pocket is accumulated in the upper  part of the valve, little by little it is compressed and its pressure arrives to water  pressure, its volume increases pushing water downwards. Following Archimede s principle the float, no longer sustained by water thrust,  will drop freeing the nozzle  hole helping the release of the air pocket, while the upper disk closes the main orifice  due to internal pressure.  FOX 3F-EO will avoid the air entrance thanks to a special system, composed of
a spring,  flat and o-ring,  whose  high sensitivity and accuracy allows  the air discharge with a DP across the valve  between 0,03 and 0,05 bar.

For air flow performances of FOX 3F-EO please refer to the chart depicted on the next page.

(**) Full polypropylene cylindrical floats to avoid deforming  phenomena at high pressure and lathe shaped to guarantee:
a) a greater sliding precision inside the body processed ribs;
b) a perfectly vertical thrust;



Working conditions
Potable water 60°C/1
58 °F Max; Maximum pressure 40 bar/580 psi; Minimum pressure 0.3 bar/4.35 psi
On request minimum pressure of 0,15 bar with the high sensitivity low pressure version

Technical features
Body and flanges in GJS  500-7 epoxy powder  coated using fluidized bed technology
Cap and  mesh in stainless steel
Seat in stainless steel Upper flat in polypropylene Nozzle in stainless steel Float in polypropylene
Nuts  and bolts in stainless steel
bin NBR
Drainage valve in stainless steel.
Spring in stainless steel.
Flat in stainless steel  / brass.