Air vent valves can discharge the air that formed into the hydraulic circuits of the heating/ cooling or domestic water systems.
What is a Air Vent Valve?
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.
How do Air Vent Valves work?
The operation of the automatic air vent valve is very simple and it is based on the principle of the floating of bodies immersed in a fluid.
When there is no air accumulation into the valve body, the float ball is in raised position and through the mechanism, it keeps the stopper under closing. The lowering of the floating level caused by the air accumulation into the valve body, involves the stopper opening and the consequent discharge that persists up to the reintroduction of the normal conditions.
If there is a lot of air in the system, the float is completely lowered and allows the air to flow out more quickly.
The air discharge is prevented by screwing the lateral plug. In normal operation conditions, the plug shall be unscrewed.
Where Air Vent Valves should be Installed?
The vent valve is a device installed to prevent negative pressure (e. g. as a result of surge pressures) in a piping system.
Vent valves are also installed at the highest points in a piping, system downstream of shut-off elements or pumps, and at the highest points in domestic installation systems.
Details of Air Vent Valves
- Sealed with O-ring.
- Designed for installation on head connections of flush manifolds.
- Brass CW617N, Ductile Iron or Stainless Steel body.
- Max. pressure: 10 bar~ 25 bar.
- Max. temperature: 120°C
- Impurities do not usually affect function as maximum float line of water is always lower than the valve seal
- Float is high temperature resistant polyethylene
- Suitable for use with glycol systems
- Can be disassembled for inspection and cleaning
Advantages of Air Vent Valves
- Protect pipelines
- Resolve air entrapment issues
- Ensures safe operations of pipelines
- Prevents bubble and air pocket formation
- Low maintenance
- Energy efficiency
