Head Calculations

[giulianom]

I am considering putting my sump in my basement instead of underneath my tank, but the sump location is a good 20' away horizontally, with about a 10-12' vertical rise between the pump inlet and the plumbing outlet.

Could someone sanity check these calculations?


Pump: Reeflo Dart Hybrid

1.5" pipe, 12' vertical and 20' horizontal run.


Calculation results:

Head Pressure 20.45 ft loss
Head Pressure 8.84 PSI
Flow Rate 2695.07 GPH
Exit Velocity 7.08 ft/sec


Calculator parameters:

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Pumps.XML pump data that I had to add:

<pump name=\"Reeflo Dart Hybrid\">
	<a>-0.0312500000</a>
	<b>0.3487103175</b>
	<c>4.6101190476</c>
	<d>72.0634920635</d>
	</pump>

Pump curve:

alt="" /></a>


Thanks!

 

[grouper therapy]

Try it at 2" pipe

 

[giulianom]

With 2" pipe, I get this:

Head Pressure 18.48 ft loss
Head Pressure 7.98 PSI
Flow Rate 4750 GPH
Exit Velocity 7.57 ft/sec


The pump inlet is 2", but the pump outlet is 1.5...

The connections on the UV are also 2".


So should I do 2" then?

 

[grouper therapy]

I would go with as large as I could. Ignore the pump outlet size it is irrelevant with as much head loss as you have. what is the shutoff height on the dart hybrid it is not much I don't think. I assume you are using it as return pump.

 

[giulianom]

Ok, I can do 2" for the return line easily enough.

Yes, the Dart Hybrid would be the return pump.


Here's the Pressure vs GPH numbers - is it 12' for the Dart?

alt="" /></a>

 

[giulianom]

There is also this on sizing guidelines from Reeflo, but I'm not really sure how to interpret the tables.

http://www.reeflopumps.com/images/tips.pdf">http://www.reeflopumps.com/images/tips.pdf</a>

Edit: Am I right in thinking that the vertical run of 10-12' is a bit too close to the top end of the Dart?

Perhaps I should consider a heavier-duty pump with a higher max head for the return, and use the Dart as possibly a closed loop.

 

[grouper therapy]

Sadly the dart will not make the lift. I would search for a pump with your head loss and desired gph falling somewhere in the middle of the curve. Pay attention to the wattage draw for longevity sake,

 

[rtackett]

I had a similar head pressure and I went with the hammerhead - the Dart will not do it.

 

[giulianom]

I believe you're all right - the head pressure is too high to get anything useful out of the Dart.

Here are some fun charts I made to compare between the Dart, and the Barracuda / Hammerhead hybrids:

Dart:

alt="" /></a>

Barracuda:

alt="" /></a>

Hammerhead:

alt="" /></a>


And the pressure chart numbers for the Barracuda / Hammerhead:

http://imgur.com/fvxwD">[IMG]http://i.imgur.com/fvxwD.gif" alt="" /></a>


Given that the BC/HH inlet and outlets are both 1.5", is it worth considering upsizing to 2" pipe?

I'll run the calculations shortly...

 

[giulianom]

Looks like the Barracuda would be slightly on the high end of its curve:

Pump Reeflo Barracuda Hybrid

Pipe Diameter 1.5 inches
Vertical Height 12 feet
Horizontal Length 20 feet
Number of 90 Degree Elbows 4
Number of 45 Degree Elbows 0
Number of Gate Valves 1
Number of Ball Valves 2
Number of Union Couplings 4
Number of Swing Check Valves 2
Number of Pipe Exits 1
Number of Pipe Entrances 1

Results
Head Pressure 35.61 ft loss
Head Pressure 15.39 PSI
Flow Rate 4590.6 GPH
Exit Velocity 12.06 ft/sec (per exit)

But the Hammerhead would be right in the middle of the curve:

Pump Reeflo Hammerhead Hybrid
Pipe Diameter 1.5 inches

Results
Head Pressure 35.1 ft loss
Head Pressure 15.17 PSI
Flow Rate 4534.07 GPH
Exit Velocity 11.91 ft/sec


The numbers go slighly down with 2" pipe and the Hammerhead, and the GPH goes way up:

Results
Head Pressure 32.26 ft loss
Head Pressure 13.94 PSI
Flow Rate 7542.38 GPH
Exit Velocity 12.02 ft/sec

 

[grouper therapy]

Your head loss #s seem off

Edit: I use the sequence 6000 which real close the barracuda/hammerhead pumps and I only get 19.2' of head loss. The fittings and horizontal you posted will no way add 24+feet of loss just not sure where the error is.

Using larger pipe definitely reduces total dynamic head loss which affords you the option to control head loss via an adjustable mechanism vs, the fixed pipe size.

 

[giulianom]

Yeah, I thought the head loss and GPH numbers were a bit odd.

I'll take a look and see.. the calculator could be off.


Here are the pump values that I put in for the Hammerhead:

<pre class="code">&lt;pump name=&quot;Reeflo Hammerhead Hybrid&quot;&gt;
&lt;a&gt;-0.0122136577&lt;/a&gt;
&lt;b&gt;0.2983172164&lt;/b&gt;
&lt;c&gt;3.8512342137&lt;/c&gt;
&lt;d&gt;100.9838085186&lt;/d&gt;
&lt;/pump&gt;</pre>


And a Sequence 6000:
<pre class="code"> &lt;pump name=&quot;Sequence 6000SEQ23&quot;&gt;
&lt;a&gt;-0.016236667&lt;/a&gt;
&lt;b&gt;0.3313&lt;/b&gt;
&lt;c&gt;-3.0725&lt;/c&gt;
&lt;d&gt;101.5283333&lt;/d&gt;
&lt;/pump&gt;</pre>

And I found the problem.. "C" is supposed to be a negative number.

Fixing those values:

<pre class="code">&lt;pump name=&quot;Reeflo Dart Hybrid&quot;&gt;
&lt;a&gt;-0.0312500000&lt;/a&gt;
&lt;b&gt;0.3487103175&lt;/b&gt;
&lt;c&gt;-4.6101190476&lt;/c&gt;
&lt;d&gt;72.0634920635&lt;/d&gt;
&lt;/pump&gt;
&lt;pump name=&quot;Reeflo Barracuda Hybrid&quot;&gt;
&lt;a&gt;-0.0301102139&lt;/a&gt;
&lt;b&gt;0.8325493876&lt;/b&gt;
&lt;c&gt;-8.3269679092&lt;/c&gt;
&lt;d&gt;84.1311335575&lt;/d&gt;
&lt;/pump&gt;
&lt;pump name=&quot;Reeflo Hammerhead Hybrid&quot;&gt;
&lt;a&gt;-0.0122136577&lt;/a&gt;
&lt;b&gt;0.2983172164&lt;/b&gt;
&lt;c&gt;-3.8512342137&lt;/c&gt;
&lt;d&gt;100.9838085186&lt;/d&gt;
&lt;/pump&gt;</pre>


Gives me much more accurate calculations for 2" pipe:

Dart
Head Pressure Loss: 12.16
Head Pressure (psi): 5.26
GPH: 680
Velocity (ft/sec): 1.08

Barracuda
Head Pressure Loss: 14.85
Head Pressure (psi): 6.42
GPH: 2728
Velocity (ft/sec) 4.35

Hammerhead:
Head Pressure Loss: 17.08
Head Pressure (psi): 7.38
GPH: 3683
Velocity (ft/sec): 5.87