At approximately 1:44 of the video, the K1 equation is used. d (nominal pipe size) and D (internal diameter of pipe) are used. d is shown as 3 (the nominal pipe size), but D is shown as 7.98. Shouldn't D be 3.068 inches? Please explain.
to calculate the necessary resistance coefficients needed when the upstream and downstream pipe sizes are the same: At 1.44 during these the PIPE line size is 8 inches but D1 is taken as 7.98? can you please explain Y?
We compare the calculated Cv to the valve manufacturer sizing table for an NPS 4 globe valve with =% trim. The table gives us the Flow Coefficients at the valve opening - percent of total travel. The Fisher valve sizing tables for a NPS 4 with equal percentage trim can be found here: www.emerson.com/documents/automation/catalog-12-en-1630608.pdf#page=119 For the purposes of this example some of the numbers were generalized.
@@FisherControlValve I have a few questions. I am new to this so bare with me if you don't mind. Why is this 75% significant? And how exactly do I find this 75% using a Cv value of 116.2 I thought it would be under 70% on the table? It's possible I'm reading the table wrong it is page 119 correct?
Also I understand that generally when sizing a valve I need it to be within a (20 - 80)% open. How does this information or does this information indicate that?
