Flow rate for 1" ...........

[chris17]

I was wondering if sombody could list the different flow rates for different size plumbing. Example...
1" = 800gph (not actual flow, just a guess)
I was just wondering if sombody could post these starting at like 3/4" up to 3"
Thank you. . . . . .

 

[msd2]

dont know all the different sizes but a 1 inch tube in theory can flow around 700gph.

 

[fishnerd]

Are you asking about gravity drain flows, or pressurized flows?
You also need to consider elbows, tees, sweeps, etc. because of back pressure or head pressure.
Remember this- (two) 1/2" pipes are not even close to equalling (one) 1" pipe.

 

[squidd]

For Gravity Drain" Flow you can safely figure...
3/4" = 330 gph
1" = 600 gph
1 1/4" = 910 gph
1 1/2" = 1300 gph
1 3/4" = 1800 gph
2" = 2350 gph
2 1/4" = 2960 gph
2 1/2" = 3650 gph
2 3/4" = 4450
3" = 5280 gph
These are "safe" numbers and you may be able to get "just a little more" out of them...( depending on your relative elevation and length of drain line) but they are a good place to start..

 

[tony detroit]

Squidd, I was always informed that 1'' flows around 800gph, is 600 true?

 

[golfish]

Originally posted by tony detroit
Squidd, I was always informed that 1'' flows around 800gph, is 600 true?
depends on how its setup

 

[fishnerd]

1 inch pvc pipe
On a gravity DRAIN you get around 600gph.
The effluent of a PUMP can easily do 3,000gph
IE- The waterfall thru your overflow to your sump can do 600gph with 1" pvc
The same 1"pvc can have water sent back at 3,000+ gph

 

[fishnerd]

A straight flow, with no elbows, Tees, etc can handle around 700gph. Anything causing friction such as an elbow or horizontal flow will cause substantial slowing of the water.

 

[squidd]

The above numbers are just concidered "safe" starting rates and have a bit of "fudge factor" built in...
I have run 740 "measured" gph through a 1" bulkhead and a Durso stand pipe...
But it was a very "fine" balance to keep flow consistant...

 

[chris17]

Thank you all for your input, so when choosing pumps to run a system the pump needs to be rated lower than the overflow. Example. . .
3 overflows with 1 1" down pipe in each will handle about 1,800 gph right. . . with no friction, just a straight shot into sump, . . . so to be safe I would get a pump rated for 1,600 - 1,700 gph correct??

 

[squidd]

Maybe....
Depends on how "high" your lifting water from the sump (head)
The size of the line or pipe you are using (restriction)
And the number of "elbows" you use to get the water to where you want (disturbs flow)
Number of elbows and head height are probably "fixed" but you can play with line size to "adjust" and balance your flow to the tank and get it to match the overflow rating...
That way (along with proper pump selection) you DO NOT NEED ball valves to adjust flow to tank...

 

[chris17]

Thats what I was also thinking too. . . . . would you mind helping me out?

 

[squidd]

OK...Need to know...
How high from sump floor to top of tank..?
How many "elbows" to get from sump, through stand and OTT of tank...??
Do you prefer submersible or external pump...??
Going back to your original question...you would be "safe" with a 1600-1700 gph pump, and most likely be "way" under powered...
With the above info we can get you much closer to your 1800 gph "Goal"...