8.4. Control valve sizing
Having obtained the control valve's pressure drop allocation from the pump head available, the further step is to size the valve. The other factors involved are flow rate and liquid relative density (specific gravity).
Valve sizing shall be based on maximum sizing capacity of 1.3 times the normal maximum flow or 1.1 times the absolute maximum flow, whichever is greater.
The valve should be selected such that the opening of the valve at Cv calculated should not be greater than 75% of total travel. For the exceptional cases, the approval of the company shall be obtained.
Basic steps for sizing and selecting the correct valve include calculating the required Cv. ANSI/ISA sizing equations and procedures, have been programed ...