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# Is there an equation that shows loss of flow with every bend/elbow

#1
02-10-16, 03:39 PM
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Join Date: Jan 2015
Location: United States
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Is there an equation that shows loss of flow with every bend/elbow

The subject like pretty much says it all.....wondering if there is a accurate way to estimate loss of floss in the pipes with each addition of an elbow etc...

thanks!

#2
02-10-16, 03:42 PM
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Join Date: Dec 2010
Location: Galivants Ferry SC USA
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What type of pipe?

Ream each pipe after its cut..
Use long sweep ells..

But with each pipe size you can only flow so many GPM..

What are you trying to do?

#3
02-10-16, 03:57 PM
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nah...just curiosity....
Using 3/4 for main pipes and 1/2 for all final connections.
Mostly working with PEX...

#4
02-10-16, 04:05 PM
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LOL I was thinking copper..

Pex nothing you can do to the pipe but increase size..

Im on a well and ran 1" trunk lines.. ( I would do the same with pex.)

Then run 3/4 to the fixtures... Then stub up in 1/2" to the fixtures..

#5
02-10-16, 04:18 PM
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Join Date: Jan 2011
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Still need to know what it is your suggesting doing.
A 3/4 line will have about double the flow of a 1/2 line.
I could see using a 1' as a main from the street but unless you trying to plumb an apartment building I see no use for 1" main runs.
https://www.huduser.gov/portal/publi...sign_guide.pdf

#6
02-10-16, 04:36 PM
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I could see using a 1' as a main from the street but unless you trying to plumb an apartment building I see no use for 1" main runs.
IMO the volume is increased.. When I was piped in 1/2" with little 3/4 from my 7gpm well I would lose pressure when anyone flushed a toilet or ran a sink when in the shower ( no balance spool mind you)..

Increasing my lines to 1" mains did away with my issues..

Kind of like gas pipe you need more volume sometimes. How do you get more volume? Increase the pipe size...

#7
02-10-16, 04:43 PM
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Also Joe that link to pex is a novel. If you are trying to point out a section to prove a point then you should specify..

Its like me saying you cant use 2 traps under a sink and posting a link to the 300 page plumbing code book with no reference...

Make sense?

#8
02-14-16, 10:24 AM
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Join Date: Jan 2015
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LOL...it was a novel but also thanks for sharing.... I read a lot of it and really helpful.
There is a section on flow loss - will red that later