Return pump outlet

[.AcroKiller.]

I have a red dragon 8.2 return pump and the output is 1 inch do you guys think If I reduce the outlet to 3/4 it will cause problems? The pump gph is 2100

 

[dbl]

If you can leave it at 1" as far "up" as possible, then convert to 3/4" say at the tank, I would think you'd be fine.

 

[mcarroll]

I have a red dragon 8.2 return pump and the output is 1 inch do you guys think If I reduce the outlet to 3/4 it will cause problems? The pump gph is 2100

"Problems" not likely....but it will add friction so your flow rate will be less.

Just curious, why reduce it? If you must, why not at least split it into two 3/4" outlets first, so less back pressure is created?

 

[.AcroKiller.]

My sump is match drill for a 3/4 pipe

 

[.AcroKiller.]

 

[.AcroKiller.]

You can see on this pictures the holes are drill exact to the pipe diameter

 

[mcarroll]

You will just have to account for the 3/4" in your head loss figures then. Flow will be less, but certainly not the end of the world.

I can't find a flow curve for your pump....if you care, you can use a head loss calc and the curve to get a decent estimate of your flow. Otherwise, just install it and measure the actual flow to see if it's OK.

2¢

 

[.AcroKiller.]

I believe is the 2400

 

[.AcroKiller.]

Or maybe the 2000

 

[.AcroKiller.]

It is the 2000. Also found this which at the bottom says the different output fittings

 

[mcarroll]

They'd have to tell you the different pressure ratings of the adapters.....might be called a "K value". I haven't really looked I guess, but don't know any companies who go to that length.

I'd just check out this friction head loss calculator and make an estimate based on that chart you found:
http://freecalc.com/fricfram.htm

BTW, that says Laguna....is the pump head and impeller also Laguna, or is that custom for Red Dragon? In other words, is only the motor block from the Laguna that generated that flow curve? (Those are the parts that dictate the actual flow rate and character.)

 

[.AcroKiller.]

They'd have to tell you the different pressure ratings of the adapters.....might be called a "K value". I haven't really looked I guess, but don't know any companies who go to that length.

I'd just check out this friction head loss calculator and make an estimate based on that chart you found:
http://freecalc.com/fricfram.htm

BTW, that says Laguna....is the pump head and impeller also Laguna, or is that custom for Red Dragon? In other words, is only the motor block from the Laguna that generated that flow curve? (Those are the parts that dictate the actual flow rate and character.)

The pump head and impeller are custom red dragon which makes the pump flow around 2100 to 2200 gph

 

[.AcroKiller.]

They'd have to tell you the different pressure ratings of the adapters.....might be called a "K value". I haven't really looked I guess, but don't know any companies who go to that length.

I'd just check out this friction head loss calculator and make an estimate based on that chart you found:
http://freecalc.com/fricfram.htm

BTW, that says Laguna....is the pump head and impeller also Laguna, or is that custom for Red Dragon? In other words, is only the motor block from the Laguna that generated that flow curve? (Those are the parts that dictate the actual flow rate and character.)

Do you think 2100gph would be too much for a 130 gallon tank I wanted to have a high flow and faster turn over rate. I don't run any refugium or any other means of nutrient transport other than skimmer and filter socks.

 

[dbl]

I agree with @mcarroll above. Get it installed and you'll be able to see what impact the reduction has on flow. If the pump is rated at 2100 gph with zero head pressure, you certainly won't be seeing that at your returns, especially since you're reducing them down to 3/4", so I personally don't think it will be too much flow.

 

[.AcroKiller.]

I agree with @mcarroll above. Get it installed and you'll be able to see what impact the reduction has on flow. If the pump is rated at 2100 gph with zero head pressure, you certainly won't be seeing that at your returns, especially since you're reducing them down to 3/4", so I personally don't think it will be too much flow.

I mean I can try to resize the hole for the sump to 1 inch and redo the pipping to 1 inch but if I do would it be too much flow for what I'm trying to accomplish ?

 

[dbl]

I can only speak for me personally, but I wouldn't do anything to that beautiful sump. I would simply reduce the output to 3/4" and let it run.

But to answer your question directly, I still do not think it would be too much flow even if you altered things and left it a 1".

 

[.AcroKiller.]

Thank you

 

[mcarroll]

I mean I can try to resize the hole for the sump to 1 inch and redo the pipping to 1 inch but if I do would it be too much flow for what I'm trying to accomplish ?

Did you try out that head loss calculator yet?

 

[mcarroll]

I wouldn't do anything to that beautiful sump.

+1

@iiluisii I would definitely run the calculations before doing anything else...even before installing the 3/4".

As the saying goes: Measure twice. Cut once.

That's for wood workers, but the idea stands up here too.

Once you get that number you can at least have an idea of the difference 3/4" plumbing will make vs 1".

Here' a generic example I made up for a 6' tall tank where the plumbing comes straight up from the pump, through two 90º elbows into the tank so you can see what to expect. (I made the most interesting lines red.)

You can see you get 15' of headloss with 3/4" plumbing, but only 5' of headloss with 1" plumbing and a 3/4" reducer on the outlet.

1" plumbing would enable A LOT more of your pump's flow

Liquid Friction Pressure Loss
Pressure Loss (psi): 6.51 Head Loss (ft): 15
Line Number: 3/4" plumbing
Date: 8/12/2016
Nominal Pipe Size: 0.75
Pipe Schedule: SCH 40
Flow Rate (gpm): 27
Viscosity (cP): 1
Specific Gravity (water=1): 1
Temperature (F): 70
Pipe Roughness (ft): 0.000016
Actual Pipe ID (in.): 0.824
Fluid Velocity (ft/sec): 16.25
Reynolds Number: 103628
Flow Region: Turbulent
Friction Factor: 0.019
Overall K: 3.66
Piping Length (ft): 6
Short Radius Elbows: 2
Pipe Exit : 1

Liquid Friction Pressure Loss
Pressure Loss (psi): 2.36 Head Loss (ft): 5.4
Line Number: 1" plumbing w/ reducer
Date: 8/12/2016
Nominal Pipe Size: 1
Pipe Schedule: SCH 40
Flow Rate (gpm): 27
Viscosity (cP): 1
Specific Gravity (water=1): 1
Temperature (F): 70
Pipe Roughness (ft): 0.000016
Actual Pipe ID (in.): 1.049
Fluid Velocity (ft/sec): 10.03
Reynolds Number: 81401
Flow Region: Turbulent
Friction Factor: 0.02
Overall K: 3.49
Piping Length (ft): 6
Short Radius Elbows: 2
Pipe Exit : 1
No. of Reducers: 1
Reducer Outlet Size (in) : 0.75

Liquid Friction Pressure Loss
Pressure Loss (psi): 2.21 Head Loss (ft): 5.1
Line Number: 1" plumbing w/ no reducer
Date: 8/12/2016
Nominal Pipe Size: 1
Pipe Schedule: SCH 40
Flow Rate (gpm): 27
Viscosity (cP): 1
Specific Gravity (water=1): 1
Temperature (F): 70
Pipe Roughness (ft): 0.000016
Actual Pipe ID (in.): 1.049
Fluid Velocity (ft/sec): 10.03
Reynolds Number: 81401
Flow Region: Turbulent
Friction Factor: 0.02
Overall K: 3.27
Piping Length (ft): 6
Short Radius Elbows: 2
Pipe Exit : 1

 

[mcarroll]

Do you think 2100gph would be too much for a 130 gallon tank I wanted to have a high flow and faster turn over rate. I don't run any refugium or any other means of nutrient transport other than skimmer and filter socks.

Too much...hard to say what's too much.

Usually the question is how much you need to get the job done. Two times up to maybe four or five times your display volume is all it takes. 2x-4x is the best rule of thumb I've heard...and it corresponds with skimmer sizes so it works well.

So 260 GPH up to 520 GPH...maybe op to 650 GPH if you really think your pipes are going to clog up over time or something.

For flow in the display tank, you really should be using powerheads like the Tunze streams and similar in 99% of cases.