The Ductile Iron Double Orifice Air Release Valve is an essential component for water transmission pipelines. Air trapped in high points of a pipeline reduces flow capacity, causes pressure surges (water hammer), and can lead to pipeline bursts or collapse. This valve automatically releases accumulated air during normal pressurized operation through a small orifice. When the pipeline is being filled with water, the large orifice opens to vent a high volume of air. If the pipeline drains (either intentionally or due to a break), the valve opens both orifices to admit air, preventing negative pressure that could crush the pipe. The valve is entirely automatic — a float rises and falls with water level inside the valve, opening or closing the orifices as needed.
Why Choose Us / Advantage
AWWA C512 Compliant: Meets American Water Works Association air valve standard.
Large Orifice Capacity: Sizing charts available to match pipeline flow and pressure.
Anti-Slam Device: Optional slow-closing mechanism to prevent slamming when float drops.
Debris Resistant: Large float design resists sticking from water debris.
Tested: 100% air and water pressure tested before shipment.
Technical Data
★ Type Double Orifice (Air & Vacuum)
★ Body Ductile Iron QT450
★ Float Stainless Steel 304 / 316
★ Seat EPDM / NBR rubber
★ Small Orifice Diameter 1.6mm – 4mm
★ Large Orifice Diameter 25mm – 100mm (depending on size)
★ Pressure Range PN10 / PN16 / Class 150
★ Size Range DN50 – DN300
★ Connection Flanged (EN/ANSI) or Threaded (BSP/NPT)
Applications
● High points of long-distance water transmission mains
● Pump station discharge headers
● Gravity flow irrigation canals (converted to pipe)
● Wastewater force mains
● Fire water ring mains
