NBN EN 1267:2012

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 zeta 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 zeta 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.