Gas powered water pump questions

   #1  

hartmacw

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I am new to the world of water pumps (as you will see), never have owned one. Not new to country living though. Here in Virginia we're suffering through a drought and my gardens are withering. I have been watering from our well sparingly to keep things alive but I don't want to do that too much.

I have a decent size pond with relatively clean water and it has never gone dry. I also have relatively flat land. I am trying to figure out if I can pump from the pond directly to my gardens. It's a horizontal distance of approximately 500'. I know, that's a lot. However, the good news is that the elevation change (lift) is only around 5-8' max over the entire distance. I have tried to do a lot of reading and it seems my biggest enemy is going to be friction loss based on pipe size. If I read the chart correctly, I'd be adding 13' of loss per 100' (2" pipe), for a total of 65' + 8' = 73' + whatever the fittings and connectors have on the system. The pumps I'm looking at are rated for 90' head lift or a little more so the math seems to suggest it *could* work - unless (likely) I'm missing something.

If I end up going this route I would eventually bury the line most of the way for a permanent system. But running 2" line 500' is going to be prohibitively expensive and time consuming for now, not to mention the ground is like concrete. Option 2 is to repurpose a 275 gallon water tank that I can put on my trailer, pump that full in just a minute or two, and then haul to the gardens where I can use a small electric pump to distribute it. Obviously less work overall but more time consuming going back and forth.

I am looking at several brands of 2" pumps that range from about 160GPM up to 180 in some cases. Is it even reasonable to consider going direct to the gardens over this amount of distance and lift? Could I chain two pumps together? Sorry if these are dumb questions, this is a new idea. Thanks in advance.
 
   #2  

Sawyer Rob

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Pumping horizontally isn't a problem at all, what can be a problem is, how far the pump has to "pull" the water up to the pump.

If your pump is next to the pond without much lift, the pump will have no problem pushing the water further than 500 feet!

IF you want a longer lasting 2" pump, buy a better brand like Honda or Kubota, they will last a lot longer than the cheaper brands, even if the cheaper brands come with a better motor, like a Vanguard or Honda. The pump bodies are better on the better brands...

SR
 
   #3  

denchen

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OK, so sorry about the metric but its what we talk a bit this side of the `pond`. You say the pump will do 90ft head, well that`s about 27 metres so 2.7 bar or about 40 psi. At that pressure it would do your 500 ft, although you would loose a fair bit of pressure as you say due to frictional loss. More important though is each pump is only capable of so much output, and you should keep the lift from the water level to the pump as near as you can. A pump can only lift a max of 10 metres in theory but 8.5 is about all you`ll get, now if you lift say 4 metres, in effect you use half of the pumps energy simply getting the water to the pump. Lift is not the length of the suction hose but the horizontal distance between the pump level and the water level.
 
  
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#4  
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hartmacw

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VA
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Thanks for you helpful replies. The pump would be right at the pond and have no more than 2' of lift, maybe not even that. If getting it to the gardens isn't a problem, then I can deal with some loss of pressure. I am pretty confident that I'd still be left with way more pressure than I currently have off of our well head, which is only doing like 5 GPM. If I run thru the house I get better pressure because I'm coming thru the pressure tank first, but I bet it still not more than 10 GPM. At that pressure, three sprinklers will already cover the garden.

Sounds like the mechanics and math indicate this might have a good chance at working. I think I might give it a shot. I always have my fall back plan of pumping a tank on my trailer and hauling to garden. Thanks again. I thought I was dealing more with a distance problem than a lifting problem, but alas that's why us dummies ask.
 
   #5  

ponytug

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Have a look at a pump flow vs pressure chart for the pump(s) are considering. Add in the loss of pressure for your pipe diameter and length, and see whether the flow and pressure at the outlet is what you want. A pump with a 90' lift might have zero gpm flow at 90' of lift. Don't forget to add for some pressure / flow at the garden. Most people expect a garden hose to gush, which is 20+psi (46').

You might consider a tank at the garden, so you could pump from the pond quickly, and then drip /flood irrigate from the tank.

All the best,

Peter
 
   #6  

groundcover

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I run a 1 1/2 Honda pressure pump into 1 1/2 poly pipe around the perimeter of my property with tees and hose bibs strategically placed around the yard. Works perfectly.
 
   #7  

ponytug

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I run a 1 1/2 Honda pressure pump into 1 1/2 poly pipe around the perimeter of my property with tees and hose bibs strategically placed around the yard. Works perfectly.
Can you help @hartmacw by posting your model number?

All the best, Peter
 
   #9  

oosik

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I have a Honda 2" trash pump. It pumps max around 185 gpm. I use it to pump down a small pond that forms on my property. It discharges 500 feet away thru a 2" flexible, roll up hose. This could be used to flood irrigate or fill a large tank for a more controlled irrigation program.

The beauty of my system - no ditches to dig, no permanent installation, when finished just roll up the hose, winterize the pump and put everything into storage.
 
   #10  

Wagtail

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I have a Honda 2" trash pump. It pumps max around 185 gpm. I use it to pump down a small pond that forms on my property. It discharges 500 feet away thru a 2" flexible, roll up hose. This could be used to flood irrigate or fill a large tank for a more controlled irrigation program.

The beauty of my system - no ditches to dig, no permanent installation, when finished just roll up the hose, winterize the pump and put everything into storage.
I would advise installing a water tank to augment your irrigation plan. A 5000 litre 'poly' tank is very inexpensive... at least in Tassie/Australia.
 
 
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