Anti-siphon trap vent device definition
Anti-siphon trap vent device means a device which automaticallyopens to admit air to a fixture drain above the connection of the trap arm so as to prevent siphonage, and closes tightly when the pressure within the drainage system is equal to or greater than atmospheric pressure so as to prevent the escape of gases from the drainage system into the mobile structure.
Anti-siphon trap vent device means a device which automatically opens to admit air to a fixture drain above the connection