Issue regarding the origin of the calculation formula for the control valve CV
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Everyone, we are currently calculating the discharge volume of the safety valve, which relates to the condition where the control valve is fully open due to a failure. According to the calculation formula in HG/T20570, the results are extremely large; some people prefer to use the CV value of control valves to calculate the flow rate inversely. The price is relatively affordable. The attached figure is a screenshot of the formula. I would like to know the origin of this formula. Some people say that it uses the calculation formulas recommended in IEC 60534-2-1 or ANSI/ISA-75.01.01. Since I am not an expert in process control, I would appreciate it if everyone could check whether this formula indeed comes from these standards. Are there any standard screenshots? Under normal circumstances, when the control valve fails and operation is at full capacity, how do you calculate the discharge volume of the safety valve?
I’ve encountered the same issue as well: calculating the discharge volume of the safety valve in case of a fault in the control valve
This post was last edited by hjame on 2022-11-20 at 10:59. The formula for calculating the Cv of control valves is derived from IEC 60534-2-1-2011 (cor 2015); the 2011 version is the latest one. It relates to Industrial-process control valves – Part 2-1: Flow capacity, which provides formulas for calculating fluid flow under installed conditions. The formulas vary slightly depending on the operating conditions; they are classified into compressible and incompressible types based on the state of the medium. For reference, the relevant standard is GB/T 17213.2-2017: Industrial-process control valves – Part 2-1: Flow capacity, formulas for calculating fluid flow under installed conditions.