Vacuum breaker 38VB/AR

Cla-Val Vacuum Breakers are reliable and economical pipeline surge control components, requiring no regular maintenance. Standard valves are designed to open with minimal (1/4 psi) pressure differential across the orifice. Higher or lower relief settings are available. The Vacuum Breaker Valve (Large orifice combined with Air Release Valve (small orifice) are normally closed. But when installed at points where water column separation can occur, both orifices open admitting air into pipeline, then instantly close to trap air and thereby cushioning rejoining of the water column. In this manner severe pressure surge/water hammer is prevented as the system returns to normal operation. Simultaneously the small orifice Air Release Valve opened due to vacuum and stays open venting the discharge of trapped air from pipeline slowly until gradual normal pipeline pressure is achieved. Various small orifice are available. See small orifice chart. Water column separation in a pipeline may create high levels of vacuum only momentarily, but severe damage, such as a pipeline rupture can occur when the water column rejoins. Also momentarily vacuum conditions can easily cause a thin wall pipeline or sealed water tank to collapse due to vacuum when draining fluid. Metal to Buna-N® insures “drop tight” seal at any pressure. For these reasons it is sound engineering practice to use Cla-Val Vacuum Breaker Air Release Valves to prevent water column separation in pipelines and collapse of tanks.