Series 288A-DM Anti-Siphon Vaccum Breakers for Deck/Equipment Mounted applications prevent the reverse flow of polluted water from entering into the potable water supply due to backsiphonage. Features a lightweight, durable disc float which closes the atmospheric vent to prevent spilling under all rates of flow. Ideally recommended for low flow installations such as laboratory equipment. They also contain a durable silicone disc which has high heat and water hammer shock resistance and assures tight seating with the lightest of seating contact. A full-size orifice assures pipe size capacity. Consists of a brass body construction. Maximum Pressure: 125psi (8.6 bar).