Dealing with irrigation pressure loss over distance and hills.

[Shadow_storm56]

I'm not sure how many other farmers have this issue but on our farm a big irrigation problem is pressure loss over distance. We are on a hill so from the pump to the highest point is like 60-70ft high. 6 inch underground irrigation pipe, no issue running sprinklers and lots of them as they generally don't need huge pressure. But my irrigation reel which we use alot does not work well on lower pressure. So I can run like 10Ha of sprinklers just fine at like 2100 RPM but to run the irrigation reel anywhere up the hill I need to run it at like 2400-2500 and diesel engines like to eat fuel at high revs or oil if they are older.... So down at my pump I would have 130-140Psi or
more and up at the reel I have like 50-70.

So all that being said we got a high pressure pto pump with some other irrigation pipe on a deal and it does 170-180p psi quite easy. So what I am doing is using it as a booster pump so rather than 1 pump running it's guts out to make pressure theres 2 both running easy. In my current spot the main pump feeding the underground line is running at 1500rpm and the pto pump is receiving about 20-30psi in. The output is around 130psi with the tractor running at 15-1600.

I'm wondering if anyone else does this? Either because of hills or just really long distances? Or if you do somthing different?

 

[skeets]

They put pumps in series like that underground all the time,, saves money and equipment

 

[GreensvilleJay]

from my aging gray cells...
for a 70' rise, you'll need a minimum of 35PSI ( that's dribbling water NOT a high pressure stream !)
you'll need MORE pressure to get water to the end of your hose(s)...

now... what kind of GPM do you need and how far away ?
distance = 'friction losss' and EVERY coupling hurts, especially elbows

this gets down to doing the 'math' and mapping out # of heads, pipe sizes, lengths, etc.

pressure(PSI) gets the water there, flow(GPM) is the amount of water

Having +-70PSI loss at the 'end of the reel' could mean too small a hose diameter for the flow you require(high friction losses).

 

[Shadow_storm56]

from my aging gray cells...
for a 70' rise, you'll need a minimum of 35PSI ( that's dribbling water NOT a high pressure stream !)
you'll need MORE pressure to get water to the end of your hose(s)...

now... what kind of GPM do you need and how far away ?
distance = 'friction losss' and EVERY coupling hurts, especially elbows

this gets down to doing the 'math' and mapping out # of heads, pipe sizes, lengths, etc.

pressure(PSI) gets the water there, flow(GPM) is the amount of water

Having +-70PSI loss at the 'end of the reel' could mean too small a hose diameter for the flow you require(high friction losses).

The 70psi is actually at the start of the reel I meant in the end of the line as in the start of the reel. It's a reel so only a couple hundred gallons per min which is nothing for the 1000 plus gpm pump but pressure loss is just sooooo bad. But some places can be as far away from the pump as 800meters and some only like 50 meters. No problem running sprinklers especially since I have lower pressure ones that work especially good up ontop the hill. But guns and high pressure items are a struggle.

My solution works I was just curious if others did this? If there were no outlets down on the low parts of the farm a person could probably go with somthing that makes like 250psi but currently that would blow everything on low parts of the farm and at the very least I couldn't get valves open.

 

[Shadow_storm56]

They put pumps in series like that underground all the time,, saves money and equipment

I have somthing similar for a greenhouse system, supply line can only take 40 psi and I need 90 at the end. So supply pump makes 40 and secondary bumps it up. Much smaller obviously lol. With so much dry conditions and so much watering I'm trying to save fuel and engine wear. So this way it's 2 engines running easy vs one running hard to still only get 70ish psi. I can get 130 no problem this way or even up to 180 but that would probably blow over my irrigation gun.

 

[Daren Todd]

I'm not sure how many other farmers have this issue but on our farm a big irrigation problem is pressure loss over distance. We are on a hill so from the pump to the highest point is like 60-70ft high. 6 inch underground irrigation pipe, no issue running sprinklers and lots of them as they generally don't need huge pressure. But my irrigation reel which we use alot does not work well on lower pressure. So I can run like 10Ha of sprinklers just fine at like 2100 RPM but to run the irrigation reel anywhere up the hill I need to run it at like 2400-2500 and diesel engines like to eat fuel at high revs or oil if they are older.... So down at my pump I would have 130-140Psi or
more and up at the reel I have like 50-70.

So all that being said we got a high pressure pto pump with some other irrigation pipe on a deal and it does 170-180p psi quite easy. So what I am doing is using it as a booster pump so rather than 1 pump running it's guts out to make pressure theres 2 both running easy. In my current spot the main pump feeding the underground line is running at 1500rpm and the pto pump is receiving about 20-30psi in. The output is around 130psi with the tractor running at 15-1600.

I'm wondering if anyone else does this? Either because of hills or just really long distances? Or if you do somthing different?

That's actually pretty typical once you factor in a decent distance or hills. You are limited to 3 options.

A: Use a closer water source with existing pump.

B: Add a booster pump like your currently doing.

C: use a bigger pump.

There is friction loss over distance in your pipe. As well as there is just only so much volume that will move through a certain diameter pipe.

Add hills to the mix, then the distance your pump will push the water falls off.

There are a couple options when it comes to a pump and it's a trade off depending on your needs.

You either have high volume, low pressure per xx of horse power.

Or high pressure, low volume using the same horse power.

Pressure and volume are determined by the pitch (angle) in the impellor.

Increasing the pitch, increases the pressure it will build. But this also decreases the volume of water that will pass through the impeller.

To increase volume as well you have to increase the size of the impeller. Which now is gonna require more horsepower to operate.

The issue your up against is distance and elevation. The pressure generated will only push the water so far before distance and elevation will cause it to stall out. So.in order to push the water further, you have to increase the pressure.

I hope this explains it in simple terms. I could have gone off into the weeds with a long explanation, but that also means confusing the heck out of people as well.

 

[Shadow_storm56]

That's actually pretty typical once you factor in a decent distance or hills. You are limited to 3 options.

A: Use a closer water source with existing pump.

B: Add a booster pump like your currently doing.

C: use a bigger pump.

There is friction loss over distance in your pipe. As well as there is just only so much volume that will move through a certain diameter pipe.

Add hills to the mix, then the distance your pump will push the water falls off.

There are a couple options when it comes to a pump and it's a trade off depending on your needs.

You either have high volume, low pressure per xx of horse power.

Or high pressure, low volume using the same horse power.

Pressure and volume are determined by the pitch (angle) in the impellor.

Increasing the pitch, increases the pressure it will build. But this also decreases the volume of water that will pass through the impeller.

To increase volume as well you have to increase the size of the impeller. Which now is gonna require more horsepower to operate.

The issue your up against is distance and elevation. The pressure generated will only push the water so far before distance and elevation will cause it to stall out. So.in order to push the water further, you have to increase the pressure.

I hope this explains it in simple terms. I could have gone off into the weeds with a long explanation, but that also means confusing the heck out of people as well.

It's good information, what I'm currently doing does work so I'm good with that. If there was no outputs near the source I could probably go with a higher pressure pump but as it currently is I already occasionally strip out valves from the force needed to open them down there.

 

[Daren Todd]

It's good information, what I'm currently doing does work so I'm good with that. If there was no outputs near the source I could probably go with a higher pressure pump but as it currently is I already occasionally strip out valves from the force needed to open them down there.

I would keep doing what your doing. If you went the jet pump route, you would need to figure out what you need for Gallons per minute/ pressure/ distance and size the pump accordingly.

Doing that could could mean big $$$$$ spent depending on the size of the pump.

 

[Shadow_storm56]

I would keep doing what your doing. If you went the jet pump route, you would need to figure out what you need for Gallons per minute/ pressure/ distance and size the pump accordingly.

Doing that could could mean big $$$$$ spent depending on the size of the pump.

Do they even make jet pumps that big? Lol

 

[Daren Todd]

Do they even make jet pumps that big? Lol

Yeah. I have a couple in the yard that will do 3,500 gpm at 130 psi or 5,000 gpms at 50 psi
Probably wouldn't like that price tag or the fuel bill since it's a 300 hp diesel. Has a 130 gallon tank that needs to be filled every 10 hrs of run time

I had another in here that would do 1800gpm at 160 psi. Was brought in to fill a city water tower during some repairs on a pump station.

Same issue though. It was a fuel slut.

I just got one in that's high volume last night that should take care of you. How does 9,000 gpm work for ya

 

[GreensvilleJay]

yeesh...
some places can be as far away from the pump as 800meters an

that's like 2400 feet, 1/2 MILE...
for sure there will be significant pressure losses.....

 

[ccoon520]

So there are a lot of things that come into play when sizing pumps. Specific gravity of the fluid, line size, how many fittings, how long of a run, suction pressure/vacuum, flow requirements, and head requirements. This is just for getting the right pump size and horsepower based on the wanted pump style (centrifugal, sump, split case, positive displacement, etc.).

If you contact a pump manufacturer they will generally send someone out to help you size and spec a pump that you can order for your application. If there is electrical power available Goulds or Durco would be a good place to start asking questions. If diesel power is the only option you'd have to reach out to a vendor that makes PTO or standalone diesel pumps (I don't have one off the top of my head).

Running a booster pump is definitely an option that is used a lot in a variety of industries, however, the downside being that you now have double the equipment to move the fluid which will have inherently higher run costs.

This calculator would probably be able help you out if you know the needed information. You can google the density and the like for water: https://www.checalc.com/calc/pump.html

 

[GreensvilleJay]

curious, just how big is this hose ? 1",2" 4" ?? or did i miss that info..?

 

[Shadow_storm56]

curious, just how big is this hose ? 1",2" 4" ?? or did i miss that info..?

6 inch

 

[Shadow_storm56]

So there are a lot of things that come into play when sizing pumps. Specific gravity of the fluid, line size, how many fittings, how long of a run, suction pressure/vacuum, flow requirements, and head requirements. This is just for getting the right pump size and horsepower based on the wanted pump style (centrifugal, sump, split case, positive displacement, etc.).

If you contact a pump manufacturer they will generally send someone out to help you size and spec a pump that you can order for your application. If there is electrical power available Goulds or Durco would be a good place to start asking questions. If diesel power is the only option you'd have to reach out to a vendor that makes PTO or standalone diesel pumps (I don't have one off the top of my head).

Running a booster pump is definitely an option that is used a lot in a variety of industries, however, the downside being that you now have double the equipment to move the fluid which will have inherently higher run costs.

This calculator would probably be able help you out if you know the needed information. You can google the density and the like for water: https://www.checalc.com/calc/pump.html

Most standard irrigation pumps seem to run up to 150psi and even at that level I can't open valves at lower parts of the farm because of the force. It's only irrigation guns or reels that need the booster though. I can make the pressure I need without it but the RPM of the diesel engine needs to be so high it starts eating fuel and dosen't like it.

 

[Shadow_storm56]

Yeah. I have a couple in the yard that will do 3,500 gpm at 130 psi or 5,000 gpms at 50 psi
Probably wouldn't like that price tag or the fuel bill since it's a 300 hp diesel. Has a 130 gallon tank that needs to be filled every 10 hrs of run time

I had another in here that would do 1800gpm at 160 psi. Was brought in to fill a city water tower during some repairs on a pump station.

Same issue though. It was a fuel slut.

I just got one in that's high volume last night that should take care of you. How does 9,000 gpm work for ya

Well the 3500gpm would be amazing on a frost night when I need to run alot of strawberry fields at the same time. For that my main line has 2 pumps totaling 2000GPM+ and a couple smaller stand alones. Also 160 psi still would only get me like 90 at the furthest points.

 

[GreensvilleJay]

yeesh a 6" hose that's 2400' long ! Reminds me of the 'goldrush' program where they have HUGE diesel powered pumps to transfer water to their machines.
has to be several online sites to calculate the pressure loss....

 

[Daren Todd]

Well the 3500gpm would be amazing on a frost night when I need to run alot of strawberry fields at the same time. For that my main line has 2 pumps totaling 2000GPM+ and a couple smaller stand alones. Also 160 psi still would only get me like 90 at the furthest points.

Are those 2 pumps in line or or separate lines?

 

[Daren Todd]

Well the 3500gpm would be amazing on a frost night when I need to run alot of strawberry fields at the same time. For that my main line has 2 pumps totaling 2000GPM+ and a couple smaller stand alones. Also 160 psi still would only get me like 90 at the furthest points.

Max flow rate through a 6" pipe is only around 1200gpm. And that is pushing it. 8" pipe is 2000 gpm. Even when increasing the pressure, you can only squeeze so much fluid through it.

 

[Shadow_storm56]

Max flow rate through a 6" pipe is only around 1200gpm. And that is pushing it. 8" pipe is 2000 gpm. Even when increasing the pressure, you can only squeeze so much fluid through it.

Theres essentially a pump on each end and really only 1200gpm at 150psi?? I thought it was like 8000gpm