The overflow valve is characterised by the fact that it ensures a continuous and quiet pressure reduction when used on tanks for the storage of cryogenic liquefied technical gases such as argon, oxygen, nitrogen or carbon dioxide. The overflow valve is adjusted to a pressure below the set pressure of the safety valves and thus prevents the safety valves of the tank from reacting. Using the overflow valve of type 2580 ensures that the amount of gas that is discharged is no greater than that generated in the tank due to the heat input. When tapping the gas, the valve closes so that no gas is lost unnecessarily. The overflow valve is easily fitted to the lower connections of the ball diverter valve. The connection pipe elbow required for this purpose can be included in the delivery.