What is the purpose of a pressure vacuum breaker (PVB) in backflow prevention?

What is the purpose of a pressure vacuum breaker (PVB) in backflow prevention?

• A. To prevent back-siphonage from the irrigation system into the potable supply.
• B. To regulate backflow pressure.
• C. To filter irrigation water.
• D. To increase irrigation area.

Answer: (A)

A pressure vacuum breaker is designed to protect the potable water supply from backflow caused by siphonage in an irrigation system. It works by providing an air inlet that automatically opens when line pressure drops, breaking any vacuum that could pull irrigation water back into the drinking water supply. When pressure returns, the valve reseals and normal flow continues, preventing contaminated water from entering the supply. It’s not about regulating pressure, filtering water, or increasing irrigation area, but specifically about stopping back-siphonage. Regular maintenance and proper installation are important to keep the air inlet and seals functioning.

A pressure vacuum breaker is designed to protect the potable water supply from backflow caused by siphonage in an irrigation system. It works by providing an air inlet that automatically opens when line pressure drops, breaking any vacuum that could pull irrigation water back into the drinking water supply. When pressure returns, the valve reseals and normal flow continues, preventing contaminated water from entering the supply. It’s not about regulating pressure, filtering water, or increasing irrigation area, but specifically about stopping back-siphonage. Regular maintenance and proper installation are important to keep the air inlet and seals functioning.