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Rapid Initial Air Vents for Liquid Processes (VAS & VA Series)

Rapid Initial Air Vents for Liquid Processes (VAS & VA Series)

Overview

Swiftly discharge all air/gas in pipes upon startup

Rapid initial air vents feature a large orifice, allowing them to discharge large quantities of air in a short time. This makes them the ideal choice for removing air from water tanks and water supply pipes during startup.

Once the initial air has been discharged, the valve will close and typically will not open again during normal operation. However, when pressure in the pipes falls to near or below atmospheric pressure, the valve will open once more. This allows air to enter, preventing vacuum conditions from forming within the pipes and allowing liquid to be easily passed downstream.

Though rapid initial air vents are able to discharge large quantities of air quickly, once the valve closes, it will not open again as long as a pressure differential is maintained. If it is necessary to continously discharge air during normal operation, please use this product together with an automatic air vent.


Rapid Initial Air Vents for Liquid Processes (VAS & VA Series)

Features

Rapid Initial Air Vents (all series)

  • Simple construction with no levers or hinges
  • Only one moving part: the Free Float®. This eliminates concentrated wear and provides long service life.
  • Can function as a vacuum breaker by opening to let air in when a vacuum forms
  • Provides a tight, reliable seal
  • Precision-ground float and rubber valve seat
Rapid Initial Air Vents for Liquid Processes (VAS & VA Series)

Applications

Rapid initial air vents are suitable for:

  • instances where there is a need for the rapid discharge of air upon system startup
  • processes which require expedited water supply
  • water supply pipes, water tanks, water pumps, fire extinguishing systems (VAS, VA)

* Once the valve closes after discharging initial air, it will not open again, even if air enters the air vent. If air is expected to accumulate during normal operation, please use together with an automatic air vent.



Utilization Examples

Rapid Initial Air Vents for Liquid Processes (VAS & VA Series)

Lineup

Applications Type of vent required
Rapid initial air vent Automatic air vent
Water supply pipes, water tanks, etc.
Fan coils, radiators, etc. -
Water pumps, fire extinguishing systems, etc. -

Purpose of use Compatible fluid Operation pressure (mpag) Max. discharge capacity (l/min) Body material Model Product photo Product specifications
Rapid discharge of initial air only Water, hot water 0.01-1.0 180 Cast iron VAS (20 mm) Rapid Initial Air Vents for Liquid Processes (VAS & VA Series) 331 kb
500 VAS (40 mm)
1400 VA1 Rapid Initial Air Vents for Liquid Processes (VAS & VA Series) 397 kb
3200 VA3
5600 VA4
11000 VA5

* When air is at 20°C, under atmospheric pressure, and pressure differential is 0.1 MPa.

Operation Animation

VA Series

When water is pumped through the system, the initial air inside the piping is pushed into the air vent by the pressure of the flow. The float remains in the lower part of the air vent, allowing the valve to remain open and air to be rapidly discharged.

After the initial air has been discharged, water begins to flow into the air vent, causing the float to rise and close the valve.

Once the valve closes, it will remain closed and will no longer discharge air even if more air flows in and the water level inside the air vent drops.

Only when the pressure inside the vent approaches vacuum conditions will the valve open again, allowing air to enter and water to drain.



Free Float® & 3-point Seating

Free Float®

These products contain no levers, hinges, or other components which may typically cause valves to malfunction. As the Free Float is the only moving part, wear and malfunctions are minimized. The float surface provides a nearly infinite number of valve faces to close against the seat, allowing the valve to excel in durability.

3-point Seating

3-point seating supports the high-precision ground float at 3 separate points when the valve is closed, allowing for an extra tight seal. (VS1A only)


Free Float® & 3-point Seating