Quote Originally Posted by alacheesu View Post
I've been trying to figure this out before. How do you find the restriction over the parallel loops (from before the first Y to after the second), assuming no restriction in the Y's/tubing/etc? If X is flow rate, and f(X) equals your first "y" from above, would it be 2*f(1/2*X)?
Let's make it even simpler and translate an equation into a variable...R

R = resistance = ((Pressure drop) / (flow^2))

For serial: Rt = R1 + R2

For parallel: Rt = (R1 * R2) / (sqrt(R1) + sqrt(R2))^2