My experience with different diameter water hoses for WC

[dprais1]

Okay, I didn't actually time anything, but I can approximate well enough.

these are WC done via siphon to gravity

First hose was a 1/2" RV garden style hose, 25', to empty out about 50 gallons of water felt like 30 minutes but was probably closer to 20.

Second hose was, I believe, 7/8" typical water change style hose, 25'. maybe 10-12 minutes to empty 50 gallons.

Last and the new favorite is a 1.25" water change style hose, 25'. Bythe time I've siphoned out all the poop I'm about halfway done, So maybe 4-5 minutes (I might time this in the morning) at most to empty 50 gallons.

[brewmaster15]

Morning ,
Havent had my Java yet but theres set of equations out there that govern flow rates and diameter pipes. I am mathematically challenged most of the time but the jist of it is small increases in inside diameter pipes dramatically increases in flow rates.

Maybe this equation.? Poiseuille's Law

http://hyperphysics.phy-astr.gsu.edu/hbase/ppois2.html

Al

[dprais1]

Morning ,
Havent had my Java yet but theres set of equations out there that govern flow rates and diameter pipes. I am mathematically challenged most of the time but the jist of it is small increases in inside diameter pipes dramatically increases in flow rates.

Maybe this equation...

http://hyperphysics.phy-astr.gsu.edu/hbase/ppois2.html

Al


yeah, okay. you lost me at "Poiseuille's Law":confused:

I'll just leave it as "a little bit wider hose moves a lot more water" So, if water changes seem to take too long get a wider hose and you can decrease the time at least in half pretty easily

[dprais1]

yeah, okay. you lost me at "Poiseuille's Law"

okay maybe not completely. 19% increase in diameter doubles the flow volume rate.

So if you are using 1/2 hose (pretty standard size) just by upgrading to 5/8 hose (also pretty standard size) you can do WC twice as fast....

someone double check please...???????????

[alron2]

Almost since the flow is a function of the cross area which is equal to the radius squared times a constant (pie for you math nuts). The radius sqared for a half inch hose is = 1/4*1/4 = 1/16 or .0625.while the radius squared of a 5/8 hose is =5/16*5/16 = .0976. Therefore a 5/8 hose has 1.58 (.0976/.0625) the cross area of a half inch hose. So I would expect a 5/8 to have about 1.58 times the flow of a half inch hose. A 3/4 hose has about 2.25 the cross area of a 1/2 inch hose.

Ron

[Twistofer]

[QUOTE=alron2;1146835]Almost since the flow is a function of the cross area which is equal to the radius squared times a constant (pie for you math nuts). The radius sqared for a half inch hose is = 1/4*1/4 = 1/16 or .0625.while the radius squared of a 5/8 hose is =5/16*5/16 = .0976. Therefore a 5/8 hose has 1.58 (.0976/.0625) the cross area of a half inch hose. So I would expect a 5/8 to have about 1.58 times the flow of a half inch hose. A 3/4 hose has about 2.25 the cross area of a 1/2 inch hose.

Ron[/QUOTE/

I believe that's "Pi" i.e. ~3.14159

[Loosir]

(pie for you math nuts).

Ok, 86583 is not for math nuts. I want one person of the 50,000 members here to tell me they have never hear of it. ;)

[alron2]

Geoff, they have heard of it, they just do not know how it is defined, nor do they care.
Ron