A vacuum breaker is an attachment commonly placed on a bibcock valve or

toilet A toilet is a piece of sanitary hardware that collects human urine and feces, and sometimes toilet paper, usually for disposal. Flush toilets use water, while dry or non-flush toilets do not. They can be designed for a sitting position popu ...

urinal A urinal (, ) is a sanitary plumbing fixture for urination only. Urinals are often provided in public toilets for male users in Western countries (less so in Muslim countries). They are usually used in a standing position. Urinals can be ...

flush Flush may refer to: Places * Flush, Kansas, a community in the United States Architecture, construction and manufacturing * Flush cut, a type of cut made with a French flush-cut saw or diagonal pliers * Flush deck, in naval architecture * Fl ...

valve A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...

, that prevents water from being siphoned backward into the public

drinking water Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, a ...

system. This prevents contamination should the public drinking water system's pressure drop. A vacuum breaker is also used in steam distribution systems to prevent collapse of steam coils and pipes by letting in air when the pipe pressure becomes sub-atmospheric. A vacuum breaker typically contains a plastic disc that is pressed forward by water supply pressure and covers small vent holes. Should the supply pressure drop, the disc springs back opening the vent holes (which let in outside air) and preventing backflow of water. A more complex valve that accomplishes much the same purpose is the backflow preventer. Vacuum

relief valve A relief valve or pressure relief valve (PRV) is a type of safety valve used to control or limit the pressure in a system; pressure might otherwise build up and create a process upset, instrument or equipment failure, or fire. The pressure is re ...

s are sometimes known as vacuum breakers.

Types of vacuum breakers

atmospheric vacuum breaker An Atmospheric Vacuum Breaker (AVB) is a backflow prevention device used in plumbing to prevent backflow of non-potable liquids into the drinking water system. It is usually constructed of brass and resembles a 90-degree elbow with a hood on it ...

consists of a check valve and an air vent. The devices allow air into the system to prevent a siphon at the point of use. Hose connection vacuum breakers are installed on faucets and hose bibbs to prevent backflow into the water supply. Pressure type vacuum breakers are similar to atmospheric vacuum breakers but have a spring-loaded check valve to allow operation of under pressure for long periods of time. Spill-resistant vacuum breakers utilize a check valve and air vent inlet that allows air to enter before the internal check valve opens, thereby preventing water spillage associated with pressure type vacuum breakers.

Applications

Vacuum breakers can be used in sewage applications as an alternative to a water seal. It utilizes a one-way membrane that acts similar to a check valve. The membrane is sensitive enough to open under the weight of four ounces of water but remains closed when no water is present above to minimize evaporation and eliminate sewer gas odors.

References

External links

Vacuum Breakers Tutorial
Vacuum breakers protect plant and process equipment against vacuum conditions, typically associated with cooling. {{Backflow Plumbing valves Backflow

Types of vacuum breakers

Applications

See also

References

External links