Make of Coppers materials, strong, rustproof, corrosions resistant, can used for long terms. It also have the functions of a check Valves and a pressure relief Valves, which can water from flowing back into the electric water heater. Valves of a water heater is a multifunctional storage type electric water heater relief Valves, suitable for electric water heaters and air sources water heaters. Discharge excesses pressure when the pressure inside the electric water heater is too high, ensuring the life of the inner tanks and avoiding the occurrence of bursting accidents. A check Valves is used to protect against overpressure in closed water. And It determines the flows direction of the mediums used, the flows of water, only allows in 1 direction., Manufacturer: WangWeN