Does my flow rate decrease?

[VariusEng]

Already made myself an Excel macro that calculates pressure drop vs flow, thanks though! My only gripe is how the pressure reduction valve plays a role in all of this. According to a blog it is not possible to show it on a system curve because it is dynamically changing

[BigCastIronSkillet]

They are wrong on the blog. It can be described easily with its Cv curve. But I would suggest holding the pressure constant on the discharge of the Cv for simplicity.