3 replies to this topic

[Christiano]

Hi,

 

I find the calculated CV requirement for a typical 2-phase flow of gas and liquid (when gas volume ratio is near to 90%), the calculated CV differs about 100 % between Masoneilan and Fisher methods...Any suggestions on your experience with Fisher Fm correction factor charts which makes it larger??

[mansari]

Control Valve sizing employing Two phase flow is tricky and Cv calculations requires good engineering judgement. Other than Fisher and Masoneilan, I hope the attached documenrt (page 3-15) would be useful for your calculations

 

[mansari]

Here is the file

Attached Files

•  SS_03.pdf   164.2KB   184 downloads

[Tom Berenger]

I will advise you to use the ISA equations, rather than Fisher. I find ISA a lot easier and all the factors and coefficients are listed for each scenarios. I have the full manual if you want me to send it to you.

 

You can also download the valve sizing software on Fisher website. What I usually do is use the ISA  equations for my hand calculations and then compare with the results from Fisher software.