Head loss calculator for closed loop

[dbrown]

Can I use the head loss calculator for a closed loop? Specifically the vertical height part?

 

[E-A-G-L-E-S]

in a true CL there is no head loss i believe

 

[BruiseAndy]

The only way there would be no head loss is if the outlet of your plumbing was the exact same outlet of your pump. Just measure from outlet of pump to outlet of water and add a foot for plumbing to play it safe.

 

[kgross]

yes you can, but with a closed loop your are not lifting the water so there is no vertical pipe, put it into the vertical length field zero and fill in all of the other fields and you should get a close aproximation to the actual flow.

Kim

 

[ChemE]

The statement that there is no head loss in a closed loop system is incorrect; there most certainly is. This loss is not from pushing against gravity though, it comes from skin friction of the piping. The higher the velocity of fluid in the CL piping the larger this loss. So, you want to ensure that your CL piping is as wide diameter as possible so that velocity is minimized.

Kim is of course correct, just take all the vertical lengths in your CL piping and add them to the horizontal length. That will produce the correct result. Don't neglect the vertical runs, just add them to the horizontal runs.

 

[E-A-G-L-E-S]

does this friction have create a "real" loss?

 

[ErikS]

Friction? Yes, just use the RC calculator & add zero for vertical height - you'll get a good estimate. Zero vertical loss in a CL but all other factors are inplay (valves, bends, etc.)

The only way there would be no head loss is if the outlet of your plumbing was the exact same outlet of your pump.

Uh-uh....nope.....water pressure down = water lift = zero vertical headpressure.

This is how canister filters work - they just move water & why they burn up in short order if you were to use them as a return pump.

 

[dbrown]

So basically use the largest possible pipe and reduce as close to output as possible?

 

[johntbyrne]

Yes and long radius 90s help too. I have designed many pneumatic convey lines and the majority of the pipe loss comes from the 90s assuming no drastic verical changes. Smooth inside pipe helps too so try to seat all the fittings all the way to avoid an inside lip.

 

[armygreen11]

If you can't find long radius 90's, two 45's work too. Or you could use spa-flex... Flexible tubing that you can solvent weld pvc fittings to. Easy to clean too, just squeeze it with some adjustable pliars.