How large of a pump?

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Brother_Bear

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Hi all,
Just wondering if anyone can help with this - I have 120' of 3/4" SCH40 PVC traveling 15' up w/24 90-degree elbows (convoluted I know...) The friction loss calculations I saw would basically double the length of pipe (with all those elbows), so how much flow do I need to get the water from the bottom to the top? 950GPH w/15' head rating did not cut it, and I don't want to install another pump just to find it's underpowered too...
Thanks in advance. =)
 
I don't have an answer for you, but what situation would you need twenty four 90° elbows??

Is moving the pump closer to the well an option? Thats an awful lot of pipe to draw the water through...
 
Perhaps I wasn't clear enough - the pump & rain barrels (cistern) are down 15' from the level of the house where I need the output. It took roughly 120' of pipe and a ton of elbows to navigate the subflooring of the house coming up through the basement - not ideal I know. Hoping a submersible with a high enough output will allow me to move the water up, but I'm open to suggestions...
In straight pipe terms it's about 220' of pipe and 15' of lift. Forget the elbows. How much output would be required?
 
You need to consult a pump manufacturer, you can obtain a pump curve chart from all makers of pumps that will tell you what the pump can deliver.
you need.

Total distance including friction loss . ( all those 90's add a segnifigant distance to the piping as a 90 is equal to several feet of straight pipe. )

required Gpm at fixtures.

total elevation gain ( head )
 
At 950 gph in 3/4" sch 40 pipe you will lose 15 PSI per 100'. Add friction loss for 220' of pipe to the 15' elevaton rise, and you need a pump that will deliver 15 GPM at 40 PSI or 92' of head. 1/2 HP 15 or 16 GPM submersible will do that.
 
Yes, very impressive reply. Valveman, is that just a chart you use, or are there lots of calculations?
 
I use a friction loss chart for that particular size and schedule pipe. I could have added up the friction of the elbows, but I just doubled the pipe length to save time. Then added the elevation to the friction loss and looked up a pump curve to match.
 

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