Head loss calculator?

[racer69]

I am thinking of buying a Dolphin 4000/3000 Amp Master external pump for my returns. My plan is to use two wye fittings. Coming out of the sump I have two 1" lines that I will wye into a 2" that goes into the pump. Coming out of the pump I will have a 2" wye going into two 1" returns that will neck down to 3/4" returns.

The head loss calculator does not allow for two lines using a wye connection, so can I just use the calculator with a 1-1/2" return since it is going to be split into two 3/4" returns with the wye.

If this is confusing, let me know and maybe I can explain a little better.

 

[Clown-N-Around]

Two 3/4" have a lot more resistance (head loss) than one 1 1/2". I would leave the size as 3/4" and count the total length in both branches.

 

[Jagermeister]

Try doing the calculator for each line individually and then add the results of each line to get your total loss. You'll also have a little bit of loss at the y's but this method should get you pretty close to your total head loss.