This standard is applicable to all industrial process control valves (hereafter referred to as control valves). It establishes definitions and seat leakage classifications. It specifies the face-to-face dimensions and the requirements for inspection, testing and marking. This standard covers control valves from PN 10 to PN 100 and Class 150 to Class 600. The range of DN is according to the dimensions listed in the basic series from the EN 558-1 and EN 558-2.