This European Standard specifies the safety, construction and performance requirements for pressure regulators and pneumatic gas/air ratio pressure regulators (zero pressure regulators are included as a special type of pneumatic gas/air ratio pressure regulator), intended for use with gas burners, gas appliances and similar use, hereafter referred to as `pressure regulators'. This European Standard is applicable to pressure regulators with declared maximum inlet pressures up to and including 50 kPa (500 mbar) of nominal connection sizes up to and including DN 250 for use with one or more fuel gases in accordance with EN 437, pressure regulators which use auxiliary energy, pneumatic gas/air ratio pressure regulators, which function by controlling a gas outlet pressure in response to an air signal pressure, air signal differential pressure, and/or to a furnace pressure signal (zero pressure regulators are included as a special type of pneumatic gas/air ratio pressure regulator), gas/air ratio pressure regulators which change an air outlet pressure in response to a gas signal pressure or a gas signal differential pressure. This European Standard does not cover pressure regulators connected directly to gas distribution network or to a container that maintains a standard distribution pressure, pressure regulators intended for gas appliances to be installed in the open air and exposed to the environment, mechanically linked gas/air ratio controls, electronic gas/air ratio controls (EN 12067-2).