At a "loss" about head loss

[Wrasse-cal]

I have about 45 inches of vertical return pipe that t's off into about a foot of horizontal run. 3/4 inch pipe. 1 ball valve.

I'm at a loss about how to correctly calculate the head loss.

The best I figure is an estimate of roughly 4.75 feet, adding another foot because of the T and valve. Is this even close to being right?

I tried to use the reef central calculator as well as other calculators I found online. Maybe I'm being a bonehead, but when I input my data, I get nonsensical results.

Anyone have a easy to use online calculator?

I'm considering using the Sicce Pro line of pumps. I found the data sheet with the flow curve, but no online calculator that lets me select those pumps.

 

[McArcher]

While that's probably a reasonable estimate, it depends on how much flow you are looking for. Minor and friction losses in pipe are dependent on velocity.
Just as the flow from a pump depends on the head loss, the head loss in the piping system depends on the flow.

 

[mlb75]

what's the output size of the pump you're looking to use? by upping the size of the pipe a bit it can make a big difference in throughput. How big is big enough is another topic but it definitely makes a difference. Keep the size as large as possible until you have to neck it down.

Sorry don't have a calculator for you though...

 

[Brew12]

I have about 45 inches of vertical return pipe that t's off into about a foot of horizontal run. 3/4 inch pipe. 1 ball valve.

I'm at a loss about how to correctly calculate the head loss.

The best I figure is an estimate of roughly 4.75 feet, adding another foot because of the T and valve. Is this even close to being right?

I tried to use the reef central calculator as well as other calculators I found online. Maybe I'm being a bonehead, but when I input my data, I get nonsensical results.

Anyone have a easy to use online calculator?

I'm considering using the Sicce Pro line of pumps. I found the data sheet with the flow curve, but no online calculator that lets me select those pumps.

I would figure it at 5ft and then go to the pump curve. How much flow are you looking for?

 

[Wrasse-cal]

While that's probably a reasonable estimate, it depends on how much flow you are looking for. Minor and friction losses in pipe are dependent on velocity.
Just as the flow from a pump depends on the head loss, the head loss in the piping system depends on the flow.

Thanks. I have a 75 gallon display. 25 gallon sump. Looking, at least for now, to be at roughly a 6x turnover. Thinking 500-600 gph would be what I want as actual output.

what's the output size of the pump you're looking to use? by upping the size of the pipe a bit it can make a big difference in throughput. How big is big enough is another topic but it definitely makes a difference. Keep the size as large as possible until you have to neck it down.

Sorry don't have a calculator for you though...

I was looking at the Sicce Pro 1500 gph and stepping it down somewhat. I was thinking I might want to increase my flow to 10x turnover at some later time.

The output will be split (with a T) via 3/4 locline to 2 3/4 inch random flow generators.

I would figure it at 5ft and then go to the pump curve. How much flow are you looking for?

Good question. I'm leaning right now to between 500-600 gph, which would be roughly 5-6 times turnover per hour. I'm estimating a head loss of about 1.5 meters ~5 feet.

With the Pro 1500, eyeballing the chart I'd be looking at maybe 3800 lph? So 990 gph. I'd shoot to throttle down the pump output to roughly 2/3 max?

With the Pro 1000, I'd maybe be looking at maybe 2250 lph? So 594 gph. I'd run pump that fully open, but be stuck if I ever decided to go to a 10x or so turnover.

 

[Brew12]

Thanks. I have a 75 gallon display. 25 gallon sump. Looking, at least for now, to be at roughly a 6x turnover. Thinking 500-600 gph would be what I want as actual output.



I was looking at the Sicce Pro 1500 gph and stepping it down somewhat. I was thinking I might want to increase my flow to 10x turnover at some later time.

The output will be split (with a T) via 3/4 locline to 2 3/4 inch random flow generators.



Good question. I'm leaning right now to between 500-600 gph, which would be roughly 5-6 times turnover per hour. I'm estimating a head loss of about 1.5 meters ~5 feet.

With the Pro 1500, eyeballing the chart I'd be looking at maybe 3800 lph? So 990 gph. I'd shoot to throttle down the pump output to roughly 2/3 max?

With the Pro 1000, I'd maybe be looking at maybe 2250 lph? So 594 gph. I'd run pump that fully open, but be stuck if I ever decided to go to a 10x or so turnover.

I would go with the 1500, and no just because that is what I am currently using. You can always dial it down using the adjustment on the pump for less flow. This will also save electricity. If you can't reduce it enough using the pump setting you can throttle it more with a valve but I doubt you would need to.

 

[Wrasse-cal]

I would go with the 1500, and no just because that is what I am currently using. You can always dial it down using the adjustment on the pump for less flow. This will also save electricity. If you can't reduce it enough using the pump setting you can throttle it more with a valve but I doubt you would need to.

Great! I'm really hoping this is a super quiet pump. How do you find it to be?

Correct me if I'm wrong, I thought that because this is an AC pump, adjusting the pump for less flow wouldn't adjust the amount of electricity used--it just opens or closes a valve? Is that not right?

 

[Brew12]

Great! I'm really hoping this is a super quiet pump. How do you find it to be?

Correct me if I'm wrong, I thought that because this is an AC pump, adjusting the pump for less flow wouldn't adjust the amount of electricity used--it just opens or closes a valve? Is that not right?

You are wrong. It is an AC pump so its speed doesn't change. However, electrical usage in a pump is tied to the work it does. Putting a valve on the intake reduces the work done by the pump which reduces the amount of energy it consumes. Putting a valve on the discharge side does reduce energy consumption by a little bit, but not as much as on the inlet.

The danger with throttling flow on the inlet is that if you throttle too much it can cause cavitation which my damage the impeller. The pump can also overheat since it relies on flow for cooling. Sicce has taken these factors into account when they came up with their design.

Mine runs quiet but it does vibrate a lot. It came with a small neoprene pad to put it on, but it was way too small to be effective. I use 1 foot of a 1" silicon tube to connect the pump to my hard piping. I took 2 pieces of left over tubing, split them on one side so I could open it up, and put one under each end of the pump. Runs completely silent now.

 

[Wrasse-cal]

You are wrong. It is an AC pump so its speed doesn't change. However, electrical usage in a pump is tied to the work it does. Putting a valve on the intake reduces the work done by the pump which reduces the amount of energy it consumes. Putting a valve on the discharge side does reduce energy consumption by a little bit, but not as much as on the inlet.

The danger with throttling flow on the inlet is that if you throttle too much it can cause cavitation which my damage the impeller. The pump can also overheat since it relies on flow for cooling. Sicce has taken these factors into account when they came up with their design.

Mine runs quiet but it does vibrate a lot. It came with a small neoprene pad to put it on, but it was way too small to be effective. I use 1 foot of a 1" silicon tube to connect the pump to my hard piping. I took 2 pieces of left over tubing, split them on one side so I could open it up, and put one under each end of the pump. Runs completely silent now.

Thanks for both the suggestion and the clarification. Very much appreciated!

Any sort of silicon tubing you would recommend? Did you use some sort of barb to thread adapter to hook it in?

 

[mcarroll]

I have about 45 inches of vertical return pipe that t's off into about a foot of horizontal run. 3/4 inch pipe. 1 ball valve.

I'm at a loss about how to correctly calculate the head loss.

The best I figure is an estimate of roughly 4.75 feet, adding another foot because of the T and valve. Is this even close to being right?

I tried to use the reef central calculator as well as other calculators I found online. Maybe I'm being a bonehead, but when I input my data, I get nonsensical results.

Anyone have a easy to use online calculator?

I'm considering using the Sicce Pro line of pumps. I found the data sheet with the flow curve, but no online calculator that lets me select those pumps.

For a simple install with normal flow levels, you're pretty safe going by the manufacturer flow curve.

If you're doing a long or otherwise more complicated installation, then you might want to run it through a friction loss calculator.

http://www.freecalc.com/fric.htm is my go-to.

You have to plug in total length of pipe, diameter, pipe material, flow rate, specific gravity, temperature, and a possible range of fittings.

It will tell you how many feet to add onto your head pressure, then you take that back to the flow curve.

Assuming you have a 100 gallon tank, 400 GPH would be about the most flow you'd need. 6.7 GMP.

A setup like you described might turn out like this:

Liquid Friction Pressure Loss
Pressure Loss (psi): 0.4 Head Loss (ft): 0.9
Line Number:
Date: 11/29/2017
Nominal Pipe Size: 0.75
Pipe Schedule: SCH 40
Flow Rate (gpm): 6.7
Viscosity (cP): 1
Specific Gravity (water=1): 1.025
Temperature (F): 79
Pipe Roughness (ft): 0.00015
Actual Pipe ID (in.): 0.824
Fluid Velocity (ft/sec): 4.03
Reynolds Number: 26358
Flow Region: Turbulent
Friction Factor: 0.029
Overall K: 3.61
Piping Length (ft): 5
Tee Flow Through: 1
Pipe Exit : 1

So add about 1 ft of head pressure to your reading from the manufacturer flow chart.

 

[Wrasse-cal]

Thank you, mcarroll. So if I understand correctly, I would only have about a foot loss of head pressure--not 5.

The upshot being that I could use a smaller pump than the Pro 1500.

 

[Brew12]

Thank you, mcarroll. So if I understand correctly, I would only have about a foot loss of head pressure--not 5.

The upshot being that I could use a smaller pump than the Pro 1500.

He is saying to take your 4ft rise and add 1 foot for piping loses for a total of 5ft.

I also agree that you may not really want that much flow. I like to run around 4 times DT volume. I just saw that you put your tank volume at 75g so I would go with the Pro 1000. I have a feeling you will want to dial that one back a bit with your current tank. If you really decide you want more later you can get a new one and keep the 1000 as a back up.

 

[Brew12]

Thanks for both the suggestion and the clarification. Very much appreciated!

Any sort of silicon tubing you would recommend? Did you use some sort of barb to thread adapter to hook it in?

This is what I use.
https://www.bulkreefsupply.com/white-soft-silicone-tubing-sold-by-the-foot.html

 

[mcarroll]

Thank you, mcarroll. So if I understand correctly, I would only have about a foot loss of head pressure--not 5.

For the sample friction loss calculation I pasted in, I rounded your actual head up to 5 feet. So after calculating friction loss, it would be 5+0.9 feet.

For what it's worth, I'm also a fan of buying the right-sized pump for what you're planning now. If plans for a higher-flow sump develop, then plan for a bigger pump.

2¢

 

[Brew12]

I rounded your actual head up to 5 feet. So after calculating friction loss, it would be 5+0.9 feet.

I believe he has 45" of vertical rise, unless I missed something.

 

[Wrasse-cal]

For the sample friction loss calculation I pasted in, I rounded your actual head up to 5 feet. So after calculating friction loss, it would be 5+0.9 feet.

For what it's worth, I'm also a fan of buying the right-sized pump for what you're planning now. If plans for a higher-flow sump develop, then plan for a bigger pump.

2¢

Thanks. What is your take on the "ideal" (highly subjective) DT/Sump turnover?

I believe he has 45" of vertical rise, unless I missed something.

That's correct.

 

[Brew12]

Thanks. What is your take on the "ideal" (highly subjective) DT/Sump turnover?



That's correct.

I like being in the 3x to 5x range. Otherwise, my sump gets too noisy. I have a 120g DT and figure I am running around 500gpm through my sump. I can run my 1500 full open but the flow between sump sections starts to act like a waterfall. I don't feel the extra flow buys me much. But then, my sump is only 13" wide.
For my 187g tank I will be using the same pump and hope to get 700gpm in a 15" wide sump. The new sump is designed a little differently so it should remain quieter at higher flows.

 

[mcarroll]

True.....my example was fictional. Just a fairly close example to show roughly how the tool works.

@p.o.t.u.s I'd put in all your actual plumbing data for all of those figures and re-run the calculation. Sorry for not saying that!

Note that the plumbing length in the calulator is not "height". It's the total length of pipe and fittings that the water will have to touch on the way to its destination, regardless of direction.

For what it's worth, if you really think there's a chance you'll run 10x flow, then go ahead and run the calculations to see what friction losses would be like at that rate. You might find it to be worth installing 1" or 1.25" between the sump and the tank vs 0.75" – even if you run a much lower flow in the short term.

While running a pump that's too large it wasteful, running plumbing that's too big just allows your pump to run achieve it's peak performance.

2¢

 

[Brew12]

You might find it to be worth installing 1" or 1.25" between the sump and the tank vs 0.75" – even if you run a much lower flow in the short term.

I'm glad you caught that. I would never run anything less than 1" for a drain or a return until I had to reduce it down.

 

[Wrasse-cal]

True.....my example was fictional. Just a fairly close example to show roughly how the tool works.

@p.o.t.u.s I'd put in all your actual plumbing data for all of those figures and re-run the calculation. Sorry for not saying that!

Note that the plumbing length in the calulator is not "height". It's the total length of pipe and fittings that the water will have to touch on the way to its destination, regardless of direction.

For what it's worth, if you really think there's a chance you'll run 10x flow, then go ahead and run the calculations to see what friction losses would be like at that rate. You might find it to be worth installing 1" or 1.25" between the sump and the tank vs 0.75" – even if you run a much lower flow in the short term.

While running a pump that's too large it wasteful, running plumbing that's too big just allows your pump to run achieve it's peak performance.

2¢

I'm glad you caught that. I would never run anything less than 1" for a drain or a return until I had to reduce it down.

Thanks! That’s a great point.