Air vent valves (also known as automatic air vent or auto vent or Air release valves and even mistakenly referred as air relief valve) are commonly used in pressurized systems to bleed the air which gets trapped in it due to emptying of pipes especially after downtime of the hydro-pneumatic / chiller pump. Similarly in gravity fed systems also when the pipe forms an inverted u shaped bend air is trapped whenever the elevated/ overhead tank becomes empty.

The varie AV21 is a simple solid float design Air Vent. The transparent chamber makes it the worlds most unique air vent that gives a visual indication of performance. This comes with the optional auto shut off valve which saves cost of a ball valve and is a super saver.

OPERATION :
AV21’s opening & closing is determined by the float movement (up-down). When there is air in the AV21’s chamber, weight of float acts on the lever (which is integral with the plunger), thus causing it to move down. In such situation the valve seat is open allowing air to be vented out.

When filling the system with water, the air which is entrapped is pushed out. And When water reaches the AV21’s chamber the float moves up due to its buoyancy and this action closes the valve seat thus preventing water from flowing out.


The AV21 can be used for a variety of applications like

  • At top of wet riser of fire fighting systems.
  • At ends of vertical uptake line (top) of hydro- pneumatic systems.
  • In HVAC lines wherever air needs to be removed automatically without wasting chilled water into the drain.
  • Other applications wherever water (liquid) is present in a pressurized system and air needs to be removed without wasting hot / cold water.
  • In hot water (Solar) systems.. Read More
  • In water distribution systems in hilly areas where pipe tends to run downwards with depressions in between thus forming an inverted “U” where air gets trapped.
  • Wherever inverted “U” bends are created - click on the link




Medium : Water & non aggressive liquids
Max. Inlet Pressure : 10 kg/cm2
End Connection : Male BSP Threaded
Size (mm) : 15, 20, 25, 32
Models : AV21-F AV21-T
Normal Operating Temp. : 80oC 45oC
Max. Occassional Temp. : 90oC 60oC
Material of Construction Chamber : Brass Plastic
Body Plate : Brass Brass
Float & Internals : Plastic / S.S. / Brass / Rubber
Width - W (in mm) : 46 53
Height - H (in mm) : 66 66

To see accessories click here

RESOURCES

How air is trapped and how air vent valve helps removal of air



Air entrapment in buildings with Hydro Pneumatic supply

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