What does the Pressure Vacuum-Breaker (PVB) address in high-hazard applications?

The Pressure Vacuum-Breaker (PVB) specifically addresses the issue of back-siphonage in high-hazard applications. Back-siphonage occurs when the pressure in a water supply system drops, typically due to issues such as water main breaks or excessive demand, creating a vacuum that pulls contaminated water back into the potable water supply.

The PVB is designed to prevent this by incorporating a delicate mechanism that opens to the atmosphere when there is a negative pressure scenario. This allows air to enter the system, thereby breaking the siphon and protecting the clean water supply from contaminants. The effectiveness of a PVB in preventing back-siphonage makes it crucial in situations where the potential for contamination from cross-connections is a serious risk, such as in irrigation systems, industrial processes, and other applications involving hazardous substances.

Overall, by effectively breaking the vacuum when necessary, the PVB serves a fundamental role in maintaining the safety and integrity of water supplies, especially in environments where contamination could have severe consequences.