The lead free Apollo™ model AVB1LF (38LF-100) atmospheric type vacuum breaker is designed to prevent contamination of potable water due to back-siphonage. This vacuum breaker is not designed for backpressure conditions or continuous pressure applications of more than 12 hr in a 24 hr period. The Apollo™ Model AVB1LF is recommended for low flow installations that use small amounts of water and should only be installed in areas where spillage of water would not cause damage.