Backyard Aquaponics
A place to discuss aquaponics

Hi All,

an interesting article about energy savings that can be made with good plumbing system design. This is something to consider to not get caught with rising electricity prices. Also make being off grid/ self sustainable easier and cheaper.

www.rmi.org/.../Download.aspx?...BigPip ... +Pumps%3A..

Cheers.

404 - not found....from iPhone anyway.

Hi,

if that previous link doesn't work try this-
http://www.rmi.org/rmi/Library%2F2011-0 ... SmallPumps

then click on 'download' - lower RH.

Cheers.

Works for me. A very good read if you know about piping it is tremendous.

Fascinating stuff. I've been interested in learning about fluid dynamics since coming across the work of Viktor Schauberger, who you might say was to plumbing what Tesla was to electrics. Shauberger's main principle was derived from an understanding of how water moves in nature - in spirals, whorls and eddies, never in the straight, narrow lines and right-angles that humans channel it through. It doesn't surprise me that this fundamental misunderstanding of water's emergent properties is costing us so dearly.

Just started reading and the first thing worth commenting for me was the bit about stopping having an old idea. My thought was I wonder if that is why AQ people have such a problem with both GBs and not removing solids in AP?

The second was designing pipes first, interesting. Oh no I don't want to redesign or comercial system again!

When show ing some engineers the schematics for our system some said that I'd oversized many of the pipes. However the reason the pipes were specified the size they were was because I'd done calculations on the cost of small pipe vs large pipe and the cost of electricity in small pipe vs large pipe and chosen the large pipe when ever the savings in the large pipe were paid for within two years. What I tended to see was that choosing a pipe size up would pay for itself within a year but the next size up would take more than 5 years due to diminishing returns. This got thrown a bit out of whack when I had to start including the cost of control valves and flow meters but the larger sizes are still worth having. The dymanic head from our system is really small which means that we are not going to be spending much money on electricity over coming friction.

I am wondering if there is a limit to the size of the pipe in relation to the power of the pump. My pump pushes 1067 GPH and I am currently using a 3/4 inch pipe. Would having a bigger pipe reduce the pumping power of the pump? Would I still be pumping the same amount of water using a 3/4 inch pipe vs a 1 1/4 inch pipe? How would I calculate how much friction a certain size pipe creates and how that affects the flow? Sorry for all the questions, I never was really a physics guy :\

Smaller pipe sizes create a greater friction loss (basically because there is more surface area of the pipe in relation to the volume). The friction loss creates a loss of pressure. In brief, you should use the larger pipe size to reduce friction loss, which means that you lose less pressure, and so can pump more fluid, or to a higher point.

I've covered this elsewhere in the forum, I'll see if I can find it.
Found it in gnash's system. Read there for the full discussion on pipe sizing.

Try this site for the calculations:
http://www.huntermac.com.au/popuppages/ ... pvc_12.pdf

Thanks bythebrook. Sorry for the late response but I have not really been around the last week or two. I was wondering if there was a maximum pipe size possible according to the strength of the pump. For example, I am having a hard time picturing my 4000 lph pump being able to use a 6 inch diameter pipe but maybe I am mistaken. Thanks again for the info! That chart is helpful in seeing the loss in flow due to friction.

I think friction is the dominant loss when you are trying to pump water horizontally, but I don't see how a small pump could pump into a wide pipe with any height either. For a vertical pipe I imagine friction is not more of a loss than overcoming the weight of the the water column above the pump.

In the oil field if you dubble the ID of a pipe you increse the the volume 4 times. Jerry

You can connect a 4000Lph pump to a 10m wide pipe and it won't make any difference to its ability to pump other than to reduce the friction loss along the length of the pipe to basically 0. Remember that when pumping you are developing pressure and pressure does not change with volume of fluid just depth.

Thanks Stuart, I think I understand why now. The pump only overcomes the weight of the water column as if it has the same cross sectional area as the pump outlet. So it's pressure only across the pump outlet area, not over the whole pipe area. The water weight otherwise is supported by the pipe surfaces, only the hole for the pump is unsupported and needs pump pressure to counteract the water weight for that hole.

Great read, I already have my ST as close to the FT as possible, only around 1500mm of oversized pipe post pump pre FT. Now I just have to find a good large diameter flexible pipe to replace the PVC with to smooth out the bends