1) Determine the calculated flow - Qmax, Qmin
2) Determine the calculated differential pressure - select the resistance ratio S value according to the system characteristics, and then determine the calculated differential pressure (when the valve is fully open)
3) Calculation of flow coefficient - select appropriate calculation formula chart or software to calculate the max and min of KV;
4) KV value selection - according to the KV max value close to the first KV in the selected product series, the preliminary caliber is obtained;
5) Opening checking calculation - ≯ 90% valve opening is required when Qmax; When Qmin, the valve opening shall not be less than 10%;
6) Actual adjustable ratio checking calculation - general requirements shall be ≥ 10; R Actual ＞ R Requirement
7) Caliber determination - re select KV value if unqualified, and re verify.
