This standard specifies a method for determining the pressure loss and fluid flow rate through valves in piping systems using water as a test fluid. This method is suitable: - for valves with low dzeta values but higer than 0,1 by determining pressure loss, with respect to fluid flow rate and density; - and to valves with equal inlet and outlet nominal sizes. Note 1: Industrial- process control valves are tested to EN 60534-2-3.