Dimensions, materials and performance requirements (including methods of test) for pressure safety valves, of nominal sizes from DN 15 to DN 40, having working pressures from 0,1 MPa (1bar) bar) to 1,p MPa (10 bar) are defined. Pressure safety valves are intended for fitting to the cold water supply of storage water heaters, having a maximum distribution temperature of 95 degC, for all energy sources. Pressure safety valves do not control the temperature and alone do not constitute the protection required fo for storage water heaters. They are not intended to act as expansion valves under normal conditions. NOTE: The use of the device specified in this standard does not override the need to use controls (e.g thermostats and cut-outs) which act directly on the power sources of water heaters.