Closed loop Dart or Pressure rated Iwaki?

[TomToro]

I currently have a Dart run closed loop and it's pretty anemic. I have the pump pushing up 3 feet and then into a 1" diameter manifold, out to 4 consecutively longer runs of 1" pipe, ending at 8 nossles.

Question:Would I be better off with a pressure rated pump in this application, even though the gph on the Iwaki is much lower than the Dart?

Dart: Max head 12' 3600gph 135 watts at 1.2 amps

Iwaki 55rlt: Max head 26.9' 1080gph 1.6 amps 185 watts

Thanks,
Tom Toro

 

[oceanparadise1]

Look into a reeflo pump its what I use and its amazing

 

[AZDesertRat]

Your problem is your plumbing. You will never get 3600 GPH through 1" PVC. Your friction loss is tremendous. You are trying to cram 60 Gallons per minute through a pipe designed for 10 GPM.
Increase the size of the discharge line to 2" then decrease to 1" at the ends of close to the nozzles.
How is the suction side plumbed? I would do at least 2" on it too.

 

[TomToro]

Your problem is your plumbing. You will never get 3600 GPH through 1" PVC. Your friction loss is tremendous. You are trying to cram 60 Gallons per minute through a pipe designed for 10 GPM.
Increase the size of the discharge line to 2" then decrease to 1" at the ends of close to the nozzles.
How is the suction side plumbed? I would do at least 2" on it too.

I agree with you. I really don't want to re-do the plumbing and was hoping a pressure rated pump would be able to 'push' more through. My intake is only 1.5".

 

[AZDesertRat]

You might get it up to 1200 to 1500 GPH with a pressure rated pump but thats about it. That may still be stretching it through a single 1" line, thats 20 to 25 GPM which is travelling like a jet engine through 1". Consider your average household water meter, 3/4" service, only delivers 13 GPM at 60 psi pressure and a 1" commercial water meter service only does 25 GPM at 60 psi. You are asking for a miracle.

The pressure rated pump will also draw about twice the watts thus higher electric bills and much higher heat gain in the tank.

 

[TomToro]

So other people with closed loops use a larger diameter pvc with their Darts? How big? 1.5 or 2"?

 

[Poseidon]

I think the dart is 1.5 in, and 2.0 out right? I think if you run 2.0 to your manifold, and then 1" from there, you will see a dramatic increase. But 1.5" to just b4 the bulkhead would give the best results.

 

[TomToro]

I think the dart is 1.5 in, and 2.0 out right? I think if you run 2.0 to your manifold, and then 1" from there, you will see a dramatic increase. But 1.5" to just b4 the bulkhead would give the best results.

Hey Mike,
That does sound the best, but since re-doing the plumbing is out of the question for me...
Here's what I was thinking:

1.5 intake from dt down to 1" into the Iwaki 55 rlt.
1" out of the Iwaki, up 1 ft and into the 1" manifold
From there, out to the 4x 1" lead pipes and into the 8 nozzles.

I'm really looking for more velocity coming out of the nozzles. The detritus just barely moves in front of them and it's hindering the barrel motion I was hoping for.

I'm going to Lowe's today to fit the Iwaki. I'll post my results.

If this works, look for a nice barely used Dart for sale, lol.

Thanks for the help, folks.

Tom

 

[TomToro]

Well, you guys can say 'I told you so' if you want. I just swapped out the Dart for the Iwaki and can't say it made a whole lot of difference. Maybe a little more velocity from the nozzles, but not enough to make up for the extra watts.

I have an unused bulkhead in the back of the tank. Maybe I'll plumb that into the existing intake pvc and give it a little more relief. That will make a total of 2.5" going into the Dart's 2" intake.

 

[Poseidon]

That was a quick Swap Tom... Jr has a Hammerhead that will make that barrel motion you are looking for, of course it is closer to 400W to run. ;)

Can you compromise and valve down 2 of your outputs, so the other two have more flow?

 

[TomToro]

That was a quick Swap Tom... Jr has a Hammerhead that will make that barrel motion you are looking for, of course it is closer to 400W to run. ;)

Can you compromise and valve down 2 of your outputs, so the other two have more flow?

I can do that and will right now. Good idea, Mike.

Yeah, I had unions on both ends so I just had to find one side to the union and fit it to the in/out of the Iwaki. I think I'll put the dart back on after I try your experiment. It's easy enough, but kind of messy. I didn't put the valves close enough to the union and a pipe full of water comes out. Duh.

Thanks,
Tom

 

[Poseidon]

No problem! I hope you are able to make it work out. Another option would be another Dart.... Could you modify the manifold to accept a separate input?

 

[TomToro]

No problem! I hope you are able to make it work out. Another option would be another Dart.... Could you modify the manifold to accept a separate input?

That made a definite difference and I'll keep it that way when I replace it with the Dart.

I could modify it and use an additional pump (Genx 40, not pressure rated) I have to power two and the dart to power the other two. Those two together will be around 200w and should push some pretty good water.

Again, thanks for letting me use your brain on this.