Vertical versus horizontal head pressure

[tony_caliente]

Any engineers out there? I would think that water traveling across any distance would impose some form of head/back pressure (on a pump). Inituitively, I would think vertical head pressure would be greater than horizontal head pressure (if there even is such a thing). I want to pump water 30ft along a level horizontal plane. Does anyone have a resource that would account for this type of pressure?

I do have a friend that is a chemical engineer in NYC and would have the answer, but thought I would consult the "collective intellect" of ARC :thumbs:

 

[enderg60]

yup you get friction losses from long lengths of pipe. Its usually about 1ft of head pressure per 100ft of pipe with PVC(although it varies for different kinds of pipes).

99% of the time with aquariums the losses from fittings and pipe length is so minimal you may as well ignore it.

 

[grouper therapy]

Friction Loss Equivalent Length - feet of Straight Pipe (ft)
Fitting Nominal Pipe Size (inches)
1/2 3/4 1 1 1/4 1 1/2 2 2 1/2 3 4 6 8 10 12
90o Elbow 1.5 2.0 2.5 3.8 4.0 5.7 6.9 7.9 12.0 18.0 22.0 26 32
45o Elbow 0.8 1.1 1.4 1.8 2.1 2.6 3.1 4.0 5.1 8.0 10.6 13.5 15.5
Gatevalve 0.3 0.4 0.6 0.8 1.0 1.5 2.0 3.0
Tee Flow - Run 1.0 1.4 1.7 2.3 2.7 4.3 5.1 6.2 8.3 12.5 16.5 17.5 20.0
Tee Flow - Branch 4.0 5.0 6.0 7.0 8.0 12.0 15.0 16.0 22.0 32.7 49.0 57.0 67.0
Male/Female Adapter 1.0 1.5 2.0 2.8 3.5 4.5 5.5 6.5 9.0 14

This will give you the fittings friction loss equivalents to static loss. Like Ender said the horizontal add very little in head loss but the pipe size can influence the friction loss considerably.

 

[grouper therapy]

Here is the link Tony much easier than the above

 

[ichthyoid]

Tony, you are correct, re: vertical vs horizontal.

If you want to do this via diy (I assume you will use PVC, probably schedule 40 or 80), then go to this link (requires Java on your PC)-

http://www.irrigationtutorials.com/faq/psi-loss-calculator.htm">http://www.irrigationtutorials.com/faq/psi-loss-calculator.htm</a>

As you can see, you may play 'what if' scenarios based on pipe diameter, flow rate etc. It assumes the density of fresh water, but seawater is not too far off for our use-IMO (~3%). This calculator will give you some idea of what you should do. This will calculate your velocity and pressure loss for you as well. It will flag you with a warning if the conditions exceed the recommended industry standard limit of 7 linear feet per second velocity, but [B]you should keep it below 5[/B]. That velocity limit will keep you away from reaching 'turbulent flow' conditions, which lead to greater losses. This tool does the math for you.
* note that flow is [B]gallons per <u>minute</u>.[/B]

FWIW-
[B]Vertical loss[/B] is due to 'head' pressure, which is the effect of gravity, but loss may also be due to the pipe resistance, especially if of small diameter.

[B]Horizontal loss[/B] (pressure drop) is due to frictional properties/resistance/turbulence alone.

Bottom line/easy solution for horizontal run-
is to use a pipe of larger diameter rather than smaller. This avoids the 'loss' due to turbulence/frictional properties of the small pipe.
Hope this helps. Have fun!

 

[tony_caliente]

All great stuff. Will be testings these metrics tomorrow morning! Thank you.

 

[fish scales2]

As well. Great links. Thanks guys

 

[roundman]

You can also use the calculator on RC for head pressure. That is what got me through my plumbing nightmare.