diameter PVC needed


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David V
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Hi all, I know there's some sort of formula but can't locate.

650gpm, rise 10', run 40' diameter PVC needed, minimum?
 

koiguy1969

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Larger pipe means less resistance no matter the pump size. For your pumps...1&1/4" will more than suffice. 1" would be fine for the 650gph. But with the 1&1/4", if you ever wanted to go bigger your set.
 

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awesome, thanks; I'm already planning for spring, but we're getting snow; this will give me the info I need for piping!

I'll probably go with 1"
 

Meyer Jordan

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Hi all, I know there's some sort of formula but can't locate.

650gpm, rise 10', run 40' diameter PVC needed, minimum?
also same data for 950gpm please
I am not sure that either pump will be strong enough to give any meaningful flow a 10'. Check the manufacturer's performance curves for these pumps.
 

DrDave

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The pump specs should give head values at various lifts. I always tell people that before you buy know what head you have to support and size your pump accordingly. Some pumps have a high flows rate but do not have great head values.
1" is a good choice and the fittings to support that size are all available at Home Depot.
 

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Hi all, I know my pump pumps b/c I've been using it for 2 years with 2" corrugated piping, which I'm replacing with PVC.

On a different topic, someone said larger diameter is always safer. However, there must be a maximum diameter as well as a minimum diameter. To illustrate what I mean, lets exaggerate for the sake of argument and say we'll use a 2-foot diameter sewer pipe hooked up to the pump, given the specifications I gave earlier. The flow would never make it. It would be interesting to find the formula for max diameter as well
 

Meyer Jordan

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Hi all, I know my pump pumps b/c I've been using it for 2 years with 2" corrugated piping, which I'm replacing with PVC.

On a different topic, someone said larger diameter is always safer. However, there must be a maximum diameter as well as a minimum diameter. To illustrate what I mean, lets exaggerate for the sake of argument and say we'll use a 2-foot diameter sewer pipe hooked up to the pump, given the specifications I gave earlier. The flow would never make it. It would be interesting to find the formula for max diameter as well
Here are a few formulas used in determining pump performance:
  • Head (ft.) = (psi x 2.31) / sp. gr. = (in. Hg.) / (sp. gr. x .88)
  • PS1 = (head (ft.) x sp.gr) / 2.31 = (.49 x in. x Hg.)
  • Velocity (ft./sec.) = (0.4085 x gpm) / [i.d. (in.) of pipe] ^ 2
  • BHP (Centrifugal) = (GMP x head (ft.) x sp. gr.) / (3960 x pump eff)
  • BHP Positive Displacement = (GMP X PSI) / (1715 x pump eff.)
or you can read this--http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&ved=0CEMQFjAG&url=http%3A%2F%2Fwww.vemcoinc.com%2Fpdf%2FTechnical%2520Library%2FCalculating%2520Pump%2520Head%25202012.pdf&ei=0_D5VNiRBIy6ogSh44KABQ&usg=AFQjCNETnkTZgNfCS00KC9h1-coTZB_ctA&sig2=ZQCgt1EATquPzykq7xXDCg&bvm=bv.87611401,d.cGU

There are, however, various charts available that delineate friction loss for piping (and fittings) of different diameter pipe that make finding the solution a lot simpler if you already know the performance ratings of the pump.
 

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