BS EN ISO 4126-11. Safety devices for protection against excessive pressure. Part 11. Performance testing Safety devices, Pressure equipment, Safety valves, Valves, Boilers, Pipework systems, Hot-water boilers, Steam boilers, Design, Helical springs, Springs, Hydraulic tests, Marking, Performance testing, Type testing, Flow, Flow rates, Volume, Mathematical calculations, Steam heaters, Installation, Pressure testing, Relief valves, Steels, Grey cast-iron, Copper alloys, Flow measurement, Thermodynamic properties