Pipe Sizing Charts and Flow Rates

[Maich]

Ok so lets say i have mmmm.... a 150 gallon tank...
If i used dual 2 inch overflow's (made of PVC of course) and had a 2000gph pump, this would work fine without any problems?

JJ

 

[CHOMPERS]

In the "Setup & Filtration" section, there is a sticky thread on how to size a pump to your tank.

I'm guessing that you don't have the tank yet. Do you have the pump?

 

[Maich]

no lol im just starting to get the stuff.... for like the sump...

 

[CHOMPERS]

yeah, I saw that in your other threads. Get as big of a tank that you can and I'll do the numbers for you.

 

[necrocanis]

ok, this thread is great, but I'm still a lil confused as to what size I'll really need. My flow rates will be right at 5000-5500 gph on two seperate pumps, a third pump for a rugf will run around 1800 gph. The sump will be gravity fed using two large pipes. Would a 3" do the trick. The pumps already have a 2" return, so I assume that will do the trick. So would a 3" pipe do 100 gpm gravity fed? I'm getting to the stage of my project where I really need to get this stuff right. If I can avoid using 4" that would help out money wise. lol, thanks for such a great thread.

 

[terrors r us]

I made a really nice chart in Excel but it turns into a mess when copying it here, so here are smaller charts and their explanations:

Cross Sectional Area (in square inches) - Pipe sizes vs. their cross sectional area. Useful for dividing flow between pipes.
size __area
1/2 = .1963
3/4 = .4418
1.0 = .7854
1.25= 1.227
1.5 = 1.767
2.0 = 3.142

Maximum Gravitational Vertical Flow - This is what we look for when sizing drains or DIY overflows. The flow under the power of gravity reaches a maximum in the same way an object reaches Terminal Velocity as it falls through the air. The gravitational force is countered by the waters viscosity (resistance to flow) and the frictional resistance of the pipe. The viscosity creates a minimum vertical length to acheive the maximum flow. If the vertical pipe length is less than the minimum, the flow rate will be somewhat less than the pipes maximum potential.
size _GPM __GPH
1/2 = 2.50 = 150
3/4 = 5.63 = 337.5
1.0 = 10.0 = 600
1.25=15.6 = 937.5
1.5 = 22.5 = 1350
2.0 = 40.0 = 2400

Min. Vertical Length
1/2 = 2"
3/4 = 5"
1.0 = 9"
1.25= 14"
1.5 = 20"
2.0 = 36"

Frictional Head Loss per 90 (measured in Feet of Head)
size_ head loss
1/2 = .00970
3/4 = .00220
1.0 = .00386
1.25= .00602
1.5 = .00878
2.0 = .00156

Anyway... Each measurement is at the pipes maximum flow rate in the Vertical Flow Rate chart. When calculating the loss for the pump side, these values are slightly more.

There is a very conservative rule when estimating head loss. It is one foot of head per fitting. This rule does not take into account flow rates, pressure, actual frictional losses, etc. It does not have to because it is too conservative. If you multiply any of the above head losses by one thousand fittings, you will be very surprised at the actual head loss. (hint: just move the decimal to the right three places.)



Gravitational Horizontal Flow This is for horizontal applications that do not rely on a pump, or the force of a vertical pipe. These flow rates are considerably less than the vertical rates because gravity does not offer a significant horizontal force. It is a balance of gravity and the viscosity vs. the cross sectional area of the pipe.
size_ GPM
1/2 = 1.563
3/4 = 3.517
1.0 = 6.253
1.25= 9.769
1.5 = 14.07
2.0 = 25.0

In this application, you would use the chart for Vertical Flow.

In this application, you would use the chart for Horizontal Flow.

For the cross sectional area of pipe you used; Pie multiplied by the radius squared............I always though is was suppost to be
pie multiplied by the diameter of the pipe not the radius squared...
Any one know for sure?????????

 

[Jgray152]

For the cross sectional area of pipe you used; Pie multiplied by the radius squared............I always though is was suppost to be
pie multiplied by the diameter of the pipe not the radius squared...
Any one know for sure?????????

To find area of a circle it is, Pie (3.14) multiplied by Radius Sqaured. (For a Fact)
Ex. Area = (12" Diameter / 2)= 6*6=36*3.14= ***113.04 sq/in ***

 

[terrors r us]

To find area of a circle it is, Pie (3.14) multiplied by Radius Squared. (For a Fact)
Ex. Area = (12" Diameter / 2)= 6*6=36*3.14= ***113.04 sq/in ***

Your 100% correct!!!!
Area of a circle = Pi x radius squared
Circumference of a circle = Pi x diameter
for our needs we use area.....
Thanks................

 

[Riv D]

CHOMPERS,
Once again,
Thank You.

 

[CHOMPERS]

ok, this thread is great, but I'm still a lil confused as to what size I'll really need. My flow rates will be right at 5000-5500 gph on two seperate pumps, a third pump for a rugf will run around 1800 gph. The sump will be gravity fed using two large pipes. Would a 3" do the trick. The pumps already have a 2" return, so I assume that will do the trick. So would a 3" pipe do 100 gpm gravity fed? I'm getting to the stage of my project where I really need to get this stuff right. If I can avoid using 4" that would help out money wise. lol, thanks for such a great thread.

A three inch pipe will give you 5400 gph. A four inch pipe will give you 9600 gph. Are the two main pumps going to be 5000ish each or a total of 5000ish? If you need to use four inch pipe for the non-pressure plumbing, you can use sch20 or sewer parts to save a bunch of money. Sewer parts aren't rated 'pottable' obviously, but they are made on the same machines as the pottable parts and are made using the exact same pvc.