3000 feet of buried poly pipe?

To consider your problem, there are a few pieces of information required.

What is the the dailywater flow (gals/day)
How many of each type of animal will be there?
What is the head?
What is the elevation change from the pond to the end point?
What is the proposed pipe length, in feet?
What is the nameplate information on the pump itself?
(goal: to look up the pump curve)
What will be the storage mechanism for the water for the animals?
What will be the control strategy for level in the tank?
The plan is for warm (not freezing weather) use?


I'm sure others have ideas ... fordy??

owhn

Lots of those questions I don't know the answers to, but I'll try ...

14 head of cattle. 15 goats.

I think the pond is lower than the highest point on the other side, but I'm not sure how much lower.

The property is a quarter mile wide and a half mile long. I was thinking that we would be talking about 3000 feet of pipe.

Well, we didn't drain the pump this winter and now it's totalled. Gonna buy a new one. The last one was 1.5 hp and the first 500 feet of pipe is 1.5 inch. We learned early on that if you hook garden hoses up, that you need to run at least three full blast at the same time or else you can have problems (garden hose stuff cannot handle that much pressure).

Storage: I was just thinking stock tanks. We've been packing water up for goats in five gallon buckets twice a day.

Control strategy? I was thinking we would try to fill the tanks once a day. Turn the irrigation system on, go up and turn the spigot on where the stock tank is and fill it. Turn it off when done.

Yes, I'm thinking that this is for the warmer times of year only. Maybe creep into the fall a little.

Say you want to fill a 100 (very small) gallon stock tank in 20 minutes. That's a fill rate of 5 gpm (gallons per minute). A one-inch diameter pipe will have a friction head loss of two (2.0) feet per 100 feet of pipe. If you have 3,000 feet of pipe that is 2.0/100 x 3,000 = 60 feet of head.

The velocity in a one-inch pipe at 5 gpm is 2.0 fps (very low), you could pump at up to 8.0 fps with plastic pipe with no problems (keep it lower for copper). However at 8.0 fps (feet per second) the pressure loss is very high, about 30 feet per 100 feet of pipe, and the pump would not be practical.

You must add to the flow pressure loss an amount for valves and fittings (assume one gate valve for shut off, one check valve to keep the prime and one float valve to control the level in the tank = est 100 feet max equivalent length of pipe - I need to look this up in a book at the office, and 100 feet equivalent length is a good estimate, though a system with lots of valves and fittings could be affected by this added item - use caution). Therefore, add another 100 feet equiv len pipe x 2.0 feet of head /100 feet of equiv pipe length = 2.0 feet of head.

The total pump head is about, 60 feet + 2.0 feet + the elevation difference between the water surface and the float valve at the tank. Let's say the height difference is 40 feet, then the total head is 102 feet.

You need to balance all these things and get the right size pipe and pump for the flow you want. There are many combinations that will work. You may want to install a bigger pipe, like 1-1/2 inch diameter or 1-1/4, check it all out, and think about what you want. A good farm supply store may be able to give you these technical details, or you can get the flow and pressure drop charts for yourself, if you want to.

Or, just do it, something will work well. Depending on the impeller size and pump characteristics, the 1.5 hp may work with a one-inch diameter pipe.

Good Luck

Alex

Paul, I had a similar set up when I was running the grazing dairy. The well was in the center of a square 160 acre piece. The paddocks were rectangles 10 acres a piece. We had an east west main line with 900 ft drops running in between a pair of paddocks. To the end of the farthest hydrant was close to 2000'. We ran down through one low spot and up again to a hill, but probably not quite as much change in elevation as you have.

We ran the system off the main well which had a 1hp submersible.

We ran 1 1/4" poly the first 300' each way on the main line, the rest was 1" poly. We didn't bury the line, just ran it down the fence lines. We tried to drain it in the winter, but usually would have a half dozen splits to fix in the spring. We used 300ft rolls.

We used Plasson quick connect hydrants every 300' in the paddocks. The tank was 75 gallons. This was for 100 dairy cows. With cattle, if they are further than 500-600 feet from water they will go as a group and mob the water tank. If you keep the water source close, only one or two will use it at a time.

Edited one more time to add that we used the full flow PVC ball valves. Put them in where it makes sense so you can isolate leaks.

Alex's posting was spot on.


You need to consider the nature of the pump design for the application you have. While there are many, many types of pumps, there are a specific few that might have merit depending upon your situation.

Three issues are relevant there in terms of pump design.

THE MANNER OF PUMP SUCTION

I believe i understood that your pump was getting its water directly from a pond.

Is this correct?
A Will your pump be inserted below the water line of your supply under all conditions?
B Will your pump have to "suck up" water from the water line?
C Is you water human drinkable quality or will it have particles (say, sand or silt)? Affects pump clearances and internal materials. Centrugal pumps are normally not "in the water", but submersible pumps are. They don't go dry when a "self priming" style is selected.

INTERPRETATION OF PUMP CURVE INFORMATION

If you look up pumps, you might want to start at the Gould's pump catalog.

Once registered, you go for the pump selection, selecting all types and all speeds, and the flow rate (5 gpm) and the head (102 ft) and you will get a series of pumps.....

Three without flags

MULTISTAGE 1HMS 3500 1HMS3 144 32 2 0.568-
MULTISTAGE 1SV_8-16 3450 8 Stage 3 HP 365 27 2.24 1.62 --- ---
MULTISTAGE 2HMS 3500 2HMS3 126 30 3 0.53 --- ---

if you examine the two whose hp rating is about 1/2 HP (the 3 hp is too much for what you need)

Then you can exanine the pump curve.

Lets say you are looking at the 2HMS3 (and later the 1HMS3)
You can use the pump curve in several ways... from the design point of 102 ft and 5 gpm, you could go up to see how much head it could provide at 5 gpm (roughly 127 ft by my eyeball) or, if you had a presure drop of only 102 feet, move horizontally to the right for a flow of someting like 20 gpm.

But what is the REAL flow? Well, there is something called a system curve, which Alex described. As the flow goes up the pressure loses increase (that is the HEAD, in feet, increases). The pump curve goes from upper left down to lower right. The system curve goes from lower left to upper right ....So,if we plotted the system curve over the pump curve, the intersection is the operating point.

You can google/ look up Hazen -Williiams equation and caclulate your system flows, if you're careful. Follow Alex's lead. For the design conditions here, we get about 6.7 gpm at something like 125 ft of head.at that point, we look down on the pump curve and note the hp rating and the NPSHr. Its higher than the .53 hp in the selection table... but far less than 1.0 hp... also your NPSHr is only 3 feet .. I'll let Alex describe that ....

Do this for the other pump. You may well want the one with a larger head capacity .... This is all part of the process...


best fortune

owhn

Leaks come form freezing, from driving over, uv attacks on pipe. Underground is better. There are different grades and types of plastic pipe....guess what , the more it costs the better it often is ....

"Currently, my first 800 feet is 1.5 inch poly pipe. Maybe I should do 1.5 for another few hundred, then 1.25 for the next thousand, and then 1 inch pipe the rest of the way ???"


I think the material cost of the pipe is really not the biggest cost you will experience ... Over five years, your electrical costs might be range from $75 to 150. Your pump costs might be 20% higher. A real designincludes a lifecyle analysis... This may be a matter of over engineering going on here. Alex has another good point .... what do you have more of: time and calculation capability OR money?

There are (at least) two schools of the "just do it" kind.

You could do the bigger stonger better theory. Not efficient, but very reliable

OR

Build it cheap, fix what breaks. Not very reliable, but if you're sorta close the first time, then you won't have to replace everything a second time.


best


owhn

The current pump (which we might be able to repair) sat about two feet above the water line. I had rigged up an intake that would float about three inches below the water line in the middle of the pond and has filters on it to keep debris out - although algae will still probably form. With the pump on and two sprinklers going, trying to use a water wand with a rossette on the end, blew the rosette off. This was about 400 feet from the source and through 50 feet of standard garden hose. Since city water is 65 psi, I would guess that this would be about 100psi. Ever since that event, we don't run the pump unless at least three sprinkers are open and ready to roll.

So my thinking is that the pump has quite a lot of push and based on the stuff I've read here, I would guess that this pump will be fine for this project.

During the summer we run the pump about two hours each morning, watering different things. I figure that we'll fill the stock tank at about the same time we are irrigating stuff, thus getting a better bang for the buck when the pump is running.

Plus, salatin has that thing where you use gravity to feed your irrigation system. I kinda like the idea of building the pond at the highest point on the property and then when the pump is run, it chips in a wee bit to the pond (or a ram pump can help fill the pond in the spring). And then that water might be able to be used gravity-feed-style without running the pump.

It seems that in the long run there are ways to get the overall system to be more efficient.

That's a good link that agmanto posted. We worked off something similar. I'm sure our leaks came from water freezing in the line, there would usually be a bulge and a split. Our frost line is close to 4' so burying would have been a job. Also, a downside to burying the line is that leaks are harder to find and fix. Do you have gophers?

As long as the line had pressure in it we had no trouble driving over it with tractors, manure spreaders, and even a concrete truck. It would be better to protect it from heavy traffic though.

If you end up with a lower flow rate than required you can compensate with a larger tank.

We got the Plasson valves and tank valves from Kentucky Graziers: http://www.kygraziers.com/kgshop/ . The tank valves are full flow, that's important. If you're pumping pond water you may have trouble with tank valves getting stuck, a filter might be needed.

I would avoid the plastic compression couplings. We used the plastic barb couplers and good hose clamps. If it's cold when you put the system together use a propane torch to heat the pipe a little. Especially if you put it underground.

We got our pipe from a Fleet Farm store. In their catalog it shows 1"x300' for $34.47. 1 1/4"x300' is $61.47. 1 1/2" x 100' is $26.99.

Another option for you might be a plastic water tank on a trailer.