Vacuum Breaker Air Inlet Valves
Pratt AirPro Max® Vacuum Breaker Valves (Series WAVB) are designed as large orifice, one way, spring loaded valves that allow air flow in only one direction (air flowing in to the pipeline). All standard valves begin admitting air at a minimal ¼ - ½ PSI vacuum to maximize vacuum breaking potential. When the vacuum condition ceases, the vacuum breaker valve disc is instantly closed against the body seat, thereby trapping air at the high point. The fast closure of the valve disc avoids any slamming which could be caused when the water column rejoins.
By equipping the Vacuum Breaker Valve with an optional AirPro Max® Series WAR Air Release valve as a special combination setup, the assembly acts as a “free air in – controlled air out” regulator. After a vacuum condition ceases and the line returns to positive pressure – the Air Release valve slowly releases the trapped air and bleeds it to atmosphere. In this manner, the pipeline is fully restored in a controlled manner to normal operating condition (pipeline fully charged with liquid media).
Series WAVB Vacuum Breaker Valves should be used:
- For high vacuum break capacity required to protect critical infrastructure (like a penstock, etc.)
- At high points in pipelines where the hydraulic gradient and flow conditions are such that a negative pressure can possibly form but where some trapped air is desired for cushioning (until bled off).
- Where water column separation is expected which may result in water hammer.
- Adjacent to any quick closing valve in a pipeline where a severe vacuum can be formed when closed.