Fluid Control Equipment
Automatic Air Vents
VC Series/VS1C/SA3
Continuously discharge air and gas that build up inside water supply pipes
Automatic air vents feature a relatively small orifice and are suitable for discharging air and other gases during normal operation. By installing them in places where air tends to accumulate, it is possible to prevent issues caused by air trapped in water supply pipes.
Air vents can also help to prevent a vacuum from forming in pipes. When the main valve is open and pressure inside the pipes falls below the pressure of the surrounding atmosphere, air will enter the valve, preventing vacuum conditions from forming and allowing liquid to be easily passed downstream.
Due to the relatively smaller discharge capacity of automatic air vents, in cases where it is necessary to discharge large amounts of air/gas rapidly upon startup, it is best to use these products in combination with a dedicated rapid initial air vent.
Air Vents Pamphlet (1930 KB)
Benefits and Features
Automatic 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 allowing air to flow in when a vacuum forms
- Provides a tight, reliable seal
VC Series
- Precision-ground float, rubber valve seat
VS1C Series
- High precision-ground float, 3-point seating
- Can be used with liquids with specific gravities as low as 0.8
SA3 Series
- Light-weight, compact
- Auxiliary valve seat enables maintenance during operation
- Provides a tight seal, even at pressures as low as 0.01 MPa
Application Areas
Automatic air vents are suitable for:
- processes which require the continuous discharge of air/gas under normal operation conditions
- water supply pipes, cooling & heating equipment (SA3, VC)
- use in small and narrow installation spaces (SA3)
- fan coils, radiators, and other air conditioning equipment (SA3)
suitable for non-water liquid processes (VSC1, non-flammable and non-corrosive liquids only)
*When rapid discharge of large quantities of air is required upon startup, please use together with a rapid initial air vent.
Product Details
| Model | Photo | Connection | Body Material | Applicable Fluids | PMO (barg) | Min. Operating Pressure (barg) | TMO (°C) | Discharge Capacity (ℓ/min)(*1) | ||
|---|---|---|---|---|---|---|---|---|---|---|
| VC2 |  | Screwed | Bronze (CAC407) | Water | 5 | 0.5 | 90 | 25 | Specifications | Manual |
| VC3 | Screwed | Cast Iron (FC250) | Water | 6 | 1 | 90 | 90 | |||
| VC4 | Screwed | Cast Iron (FC250) | Water | 10 | 1 | 90 | 380 | |||
| VS1C |  | Screwed | Stainless Steel (ASTM A351 Gr.CF8) | Water Other Liquids | 21 | 0.1 | 150 | 170 | Specifications | Manual |
| SA3 |  | Screwed | Brass | Water | 3/10 | 0.1/1 | 100 | 9.2 | Enquire | Manual |
| VS3 |  | End Clamp | Stainless Steel (ASTM A351 Gr.CF8) | Water Other Liquids | 6 | 0.1 | 150 | 110 | Specifications | Manual |
- PMO = Maximum Operating Pressure
- TMO = Maximum Operating Temperature
- The latest version of each product's instruction manual can be found on this page.
- *Capacities are equivalent capacities of air at 20 °C under atmospheric pressure.