AVK air valves for wastewater treatment
AVK combination air valves combine an air & vacuum orifice and an automatic air release orifice in one body. The innovative design with a large air gap between liquid and sealing system ensures a reliable function, even when used with aggressive liquids and liquids containing solid particles.
Dissolved air and wastewater gases can occur in pumps or in different locations along the pipeline where turbulence, hydraulic jumps or other pressure variation phenomena occur. Also, wastewater systems often contain more undissolved air and wastewater gases than regular water supply systems due to the decomposition of materials in the wastewater. Once out of solution, air and wastewater gases will not readily dissolve and will collect in air pockets at pipeline peaks.
Combination air valves combine the function of automatic air valves and air and vacuum air valves
Combination air valves combine large volume air discharge/intake whilst filling or draining a pipeline and automatic discharge of air not being dissolved in the fluid.
During filling of a pipeline, air is released through the air and vacuum orifice. During normal operation, the automatic orifice releases trapped air accumulated in the pipeline, while the air and vacuum orifice remains closed. During emptying of the pipeline, the air and vacuum orifice admits air into the system to prevent vacuum damage.
AVK offers seven main types for wastewater treatment:
- Air and vacuum valve, steel, PN16 (701/33)
- Combination air valve, steel, PN16 (701/70)
- Combination air valve, stainless steel, PN16 (701/96)
- Combination air valve, reinforced polyamide, PN10 (701/75)
- Combination air valve, reinforced polyamide, PN16 (701/95)
- Large combination air valve, steel, PN16 (701/78)
- Underground combination air valve, air valve reinforced polyamide in valve box of polypropylene, PN10 (701/79)
Underground air valve for easy maintenance
The underground air valve is a competitive solution compared to a typical chamber construction and offers convenient and fast access to maintenance from ground level, even when the system is under pressure. When maintenance is needed, the pressure is released by means of the ball valve, the knife gate shut-off valve is closed by means of the T-key, and the complete valve assembly is taken out for service or maintenance. Alternatively, the system can be backflushed on site.
Function of combination air valves
- Automatic orifice: When air bubbles appear in the valve, the float will drop, allowing air to be released. When water rises, the float will be lifted, and the valve will close.
- Air and vacuum orifice: When emptying the pipeline, the float will drop completely, allowing large volume air intake through the large orifice. When refilling the pipeline, the water flow will force the air out through the large orifice.
Features of AVK combination air valves for wastewater treatment
- Large air gap between liquid and sealing ensures reliable function
- Conical shape allows maximum air volume in a reduced valve size
- Funnel-shaped lower body prevents accumulation of deposits
- Low-weight body of steel or reinforced polyamide
- Large automatic orifice releases large volumes of air under pressure
- Spring between upper and lower float prevents unnecessary activation of the automatic function
- Drainage and flushing from external clean water source is possible
- An exhaust tube can be mounted in the threaded opening on the top of the valve
