Vacuum Breaker Air Valves

Vacuum Breaker Air Valves are spring closed, guided Piston type Air Vacuum or Large Orifice Air Valves, designed to give vacuum protection for pipelines and tanks. The valve with full flow area opens rapidly in response to a 0.017 Bar (0.25 psi) vacuum or negative pressure differential allowing large volumes of air to enter the system to equalise negative pressures. Spring closed on recovery of the negative pressure differential, air is trapped within the pipeline, cushioning surges related to column separation, to be released through Air Release Air Valves (or by other means) and a resilient seat provides drop-tight seating.

The short stroke, guided, Piston design is exceptionally robust and offers benefits of increased longevity in the most severe of applications where a guided free float or lever mechanism can become damaged over repeated high vacuum surge events.

Vacuum Breaker Air Valves are manufactured in Ductile Iron with Bronze or Stainless Steel internals, Fusion Bonded Epoxy coated internally and externally and a Buna-N or EPDM soft seat, the Vacuum Breaker is available with PN16 or ANSI flanged connections up to 30” diameter nominal bore. Designed for clean water media with an internal spring construction, or for wastewater applications with the spring mounted externally to keep free of debris and rag, the Vacuum Breaker valve design is the most compact method of severe surge protection available.

To discuss your requirement in more detail, call the MGA Controls technical team on 01704 898980 or email

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There are many variants of this product available, which we hold in stock. Free technical support is available to help specify your product.

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