This European Standard specifies a method for determining valve pressure loss coefficient and fluid flow coefficient using water as test fluid. This method is suitable: for valves with low ? values but higher than 0,1 by determining pressure loss, with respect to fluid flow rate and specific gravity; and for valves with equal inlet and outlet nominal size. Industrial process control valves are excluded from this European Standard. NOTE 1 For ? values above 6, the pressure loss coefficient inaccuracy is higher than the pressure loss caused by the test tubes. It becomes the same configuration of tests as in EN 60534-2-3. NOTE 2 If using air as test fluid, other standards e. g. EN 60534-2-3 and ISO 6358 should be referred to.