closed loop head loss?

[dantimdad]

How do I calculate the head loss in a closed loop?

I will be running a dart and an OM 4 way. 2" input that will be 4 feet above the pump and 4 1" outlets that will be 4 and 5.5" above the pump.

The main feed to the OM will be 1.5" about 2 feet long.

There will be a true union on each pipe including the input.

I will be using spa flex through and 2 - 2" elbows on the input.
There will also be one elbow on each of the 1" pipes.

I hope thi sis enough info to give me an idea of flow.

Oh, yeah, the OM is configured to where 1and3 are on then 2and4.

Thanks,
dantimdad

 

[killingseed2000]

what pump are you looking at using?

 

[dantimdad]

A Dart.

Thanks,
dantimdad

 

[gnoles]

If I understand it right, you have similar pressure pushing down on the pump as what it takes to go back to the tank. My guess is that if you go higher than the outlet, it'd lose some head, but otherwise it would just be what you lose due to pipe friction.

You might look here for those numbers... http://www.greentouchirrigation.com/pdf/fricharts.pdf

 

[dantimdad]

That's cool Gary!

According to that, I probably am going to lose very little. I think I should get around 3200+ gph.

Couple that with the 600+ gallons of return and I should have no flow issues in the 118.

Just have to fiddle with aiming the returns once it's aquascaped, but that is another thread with pics, entirely....

dantimdad

 

[stunreefer Verified Sponsor]

You lose very little to nothing in a closed loop as there is no head pressure... it's a closed - loop. As Gary mentioned pipe friction is the only downfall...

 

[FateX8]

its about friction which is caused by the surface type of the pipe and gravity
so vertical and horizontal distance and angles are the biggest factors in head pressure
the best calculator out there for the hobby is on the other site, really the only thing useful there
i believe there is also something to do with the location of the drain to the pump that matters (height) but im not 100% sure about that one

 

[dantimdad]

Since there are so many factors at play here:

3 different pipe sizes
OM 4-way
different heights to the outlets
etc.

I am just going to hook it up and see if I need to tone it down(doubtful) or add more.

If I have to add more, I will hide koralias in aragocrete sort of like tunze rocks later on.

dantimdad

 

[killingseed2000]

my setup is simuler, OM 4-way , but i have the next size pump up, barracuda. depending on placement of the holes you wont need any more flow. my is great , not finished, but have tested it for a week so far, its very very nice.

 

[killingseed2000]

you can see some of my build info here
https://www.reef2reef.com/forums/f52/seeds-75gl-7175-3.html

 

[gnoles]

I used the OM 4way with the dart and it worked well. I had a three foot tank at the time and I had to run the outlets down low and angle two of them up... when they were all aimed at the sandbed I had wandering dunes around the tank.

 

[MitchReef]

Head loss will occur due to your elbows and piping size reductions, but will be largely negligible...the RC head loss calculator should be able to calculate it based upon total fittings....