2 replies to this topic

[Diep Thanh]

A liitle bird told me that a valve should be designed to use 10-15% of the total friction loss or 10 psi, which is greater. Could you guys please explain more about that?

What will be happend if I chose the pressure drop of CV smaller than the value ( e.g. 1 psi) Is it related to lift ratio and Cv?

Thank you for your time!

[Zauberberg]

Refer to Post #2 and the attachment in the thread http://www.cheresour...c-calculations/and come back in case of additional queries.

[Diep Thanh]

Thank you for the sharing Mr.Zauberberg. However, I am concerning about the pressure drop of CV at Min and Max Case. In Nor case, I believe we are using the same rule: DP of CV should be equal or exceeded the 50% of friction loss. But how about Max. Case? They recommends 15 psi at max case. But how that value come from? What is disaster when I specify a valve at max. case 1 psi only? I will have a large control valve definitely. It will be good to control a max flowrate because it requires a lower lift ratio , right?

Please correct me if I'm wrong.

Thank you very much!

D. Thanh