Reliable, tough and easy to ese—Hydro-rain's HRA valve has it all. Anti-siphon valves that prevent drinking water from being contaminated by irrigation back?ow must be dependable. They must also be rugged enough to provide continuing protection even in punishing environments. In areas where back?ow prevention is required, Hydro- Rain’s HRA Anti-Siphon Valve is a “must have". Its advanced design incorporates a glass filled polypropolene lid able to withstand more heat that competitors PVC lid. HRA valve meets ASSE, CSA and IAPMO standards.