Altecnic 1/2" 6 bar Safety Relief Valve The Altecnic series 311 safety relief valves are used in domestic hot water systems to protect the hot water cylinder and in heating systems to protect boiler and other components. The valve is selected for the required set pressure. As the pressure rises, when the discharge pressure is reached the valve opens and discharges to atmosphere, preventing the pressure within the system reaching levels which would be dangerous for the boiler, hot water storage cylinder and any personnel in the adjacent vicinity. Key Features and Benefits: Wras Approved Category Iv Ce Mark 1 Year Manufacturer Guarantee From Installation