backflow assemblyWelcome to the Hessenauer Sprinkler Repair and Irrigation blog and website. We provide our website visitors with news, tips and advice concerning sprinkler irrigation here in Central Florida and Orlando. Today we would like to give our readers with the basics about pressure vacuum breakers (PVB’s).

A pressure vacuum breaker (PVB) is a type of backflow prevention device used to keep non-potable (or contaminated) water from entering the water supply and are used to protect water supplies from contamination or pollution.

Backflow assemblies provide protection where a potential health hazard exists. Most local building codes require the use of a backflow prevention device on all water systems. A pressure vacuum breaker is an affordable backflow option for use in residential irrigation systems.

A PVB is similar to an atmospheric vacuum breaker (AVB), except that the PVB contains what is known as a spring-loaded poppet, making it acceptable for applications that are high hazard or where valves are downstream.

PVBs usually have test cocks, to which specially-calibrated gauges are attached, in order to ensure they are functioning properly. Pressure vacuum breakers must be protected from freezing when installed outdoors.

Safety is an important reason to use a pressure vacuum breaker in the home. Since there is usually only one water system in the home for both drinking/household use and irrigation use there is always the risk contamination through cross-connections.

A pressure vacuum breaker consists of a check device or valve and an air inlet, a chamber vented to the atmosphere. The pressure vacuum breaker is installed close to the water source in the water flow before it goes into the sprinkler valves. Pressure vacuum breakers need to be installed above the highest point in the system, usually the highest sprinkler head or the highest slope in the yard.

The check valve is designed to allow water through and keep the air inlet closed during normal conditions. When the air pressure is greater than the water pressure the vented chamber opens and closes the check valve preventing backflow of water.

Again, thank you for visiting the Hessenauer Sprinkler Repair and Irrigation blog and website. If you have backflow issues such as a backflow repair or testing, contact us at 407-302-2227 today!

For more about backflow prevention devices, browse through this selection of backflow related blog posts.