Help boosting flow up large hill into tank

[PanamaJack]

New to the forum and I have read several posts that address similar questions, but I dont't see anything that is exactly the same as my situation, so I appreciate the help anyone can provide.

I'm trying to plan a pump system that can push/pull water up an approximate 600 foot 1/2" pvc line to refill a 5,000 liter tank that will be used to provide gravity fed filtered municipal water to two small houses.

Vertically the distance between the source at the road and the tank at the top of the farm is about 90 feet, so I'm running up a pretty steep incline.

My original plan was to sink a small tank in the ground a few feet from the source at the bottom of the hill, then use a 3HP submersible pump to pump that water through a three stage 20" filtration system up into the tank. That was before I found out the municipal supply had enough pressure to reach the tank (although it is very iffy and drops to zero during peak hours of use).

So, once I found out I had some (albeit inconsistent) flow to the tank, I figured I didn't need to store water at the source, which was a relief, because I didn't want to have to build a compound at the bottom of the hill to house the tank, pump and filters for security reasons.

The new plan is to use a 1/2 HP inline above ground pump from the source, through a single check valve (located at the half-way point), through the filters and into the tank. My thinking is with some municipal pressure from the source, the pump wouldn't have to work too hard to go the distance.

I'm not quite sure where to locate the pump and filtration system along the line. Do I locate it just above the check valve at the halfway point, or would it be better to locate it just before it enters the tank and pull the water up the line as opposed to pushing it, which would be the case if I located it further down the line? And, does the pump need to have pressure and volume at all times in order to do what I need the it to do?

Incidentally, since I have a pretty sizeable tank storing water up top, maybe I can set the pump to only run when the float gives the pump the signal to run, AND during off hours when there is likely to be more substantial pressure and volume availability. I don't anticipate using so much water as to need to refill that often, maybe once a week...

And...what am I missing/failing to consider?

I appreciate the help!

 

[Valveman]

The 90' of lift is the same as 40 PSI. The 600' of 1/2" pipe will cause 48 PSI friction loss at 5 GPM flow. So you would need a pump at the bottom of the hill that can supply 5 GPM at 90 PSI, or 208' of head. A pump can push water a long way, but can only suck water up 24' max, so putting the pump as close to the bottom as possible is best. I would also put a check valve on the discharge of the pump, not half way up the hill. A pump like a Goulds 5GB05 would work. You will either need to run wires from a float switch in the storage tank to the pump, or use a pressure tank/pressure switch to turn the pump on, and have a solenoid valve with float switch at the tank.

 

[Sponsor]

 

[PanamaJack]

After speaking with someone who's estimating skills are way better than mine, it appears the distance from the bottom of the hill to the tank at the top of the hill (vertically speaking) is closer to 180 feet, not 90...since I don't really have an accurate way to measure this, I think I would rather over-estimate the height that I need to climb, than to estimate it too short.

 

[Reach4]

You will want to protect your PVC from the sun.

After speaking with someone who's estimating skills are way better than mine, it appears the distance from the bottom of the hill to the tank at the top of the hill (vertically speaking) is closer to 180 feet, not 90...since I don't really have an accurate way to measure this, I think I would rather over-estimate the height that I need to climb, than to estimate it too short.

GPS measurement of altitude is not as good as horizontal position, but I think I would still use a GPS to check the altitudes.

Try to put the GPS where it will have a wide view of the sky.

You will see that the indicated altitude changes, even when the GPS is not moving. You can improve things by averaging of some sort.

 

[PanamaJack]

Thanks for the reply, valveman!

Your detailed response makes it clear to me that I will need to locate the pump somewhere near the bottom of the hill. It appears that the pump I already bought should work, but I won't really know until I try it. I may have to go to my original plan and place a smaller tank at the bottom of the hill that the municipal supply feeds, just to make sure the pump always has water to pump. Of course then I'll need a manual float for that tank to shut off the municipal supply when the smaller tank is full.

As far as a float switch, I have that, as well as a switch that detects a dry line, and if so shuts off the pump. That will be piggy backed on the pump.

I'll take your suggestion to locate the check valve on the discharge side of the pump, rather than further up the hill. I'm guessing it can be put inline before the filtration, but I still need to confirm that somehow.

The spec sheet for the pump indicates an
Operating range:
from 5 to 50 l/m with head up to 84 metres

Not 100% sure how to read this, and the graphs are like Chinese to me, but hopefully the 1/2 horse pump will push the water up that pipe and into the tank without overheating the pump. I was sure hoping I would be able to find a way to locate the pump and filters near the tank, rather than down by the road where vandals can get to it, but that would require a consistent flow of water at the pump and I cannot depend on that at all times of the day. Hence, the need for a second tank to hold the water in so the pump always has something to pump.

Looks like I still have some configuring to do, but your advice was very valuable.

Thanks

 

[PanamaJack]

Yeah, I plan on painting any exposed pipe, and the majority of it will be under 18" of topsoil. Thanks for the reminder! As far as GPS goes, I don't even know where to get a gps around here, or how much I would need to invest to get something accurate. I tried a couple of "smartphone" gps apps, and they were horribly inaccurate. I thought about floating a helium balloon up and sighting it with a level on a stick, then measuring the string but alas, there were too many trees in the way, and I couldn't find a helium balloon that didn't lose it's lift with the altitude change.

Thanks for the quick reply.

You will want to protect your PVC from the sun.


GPS measurement of altitude is not as good as horizontal position, but I think I would still use a GPS to check the altitudes.

Try to put the GPS where it will have a wide view of the sky.

You will see that the indicated altitude changes, even when the GPS is not moving. You can improve things by averaging of some sort.

 

[Reach4]

How about measuring the barometric pressure on top of the hill, and hurrying down to measure the pressure at the bottom? If you get the numbers, somebody could help with the conversion.

Pick a time when the weather is stable.

I am surprised that the smart phone GPS apps were not useful.

 

[PanamaJack]

The 90' of lift is the same as 40 PSI. The 600' of 1/2" pipe will cause 48 PSI friction loss at 5 GPM flow. So you would need a pump at the bottom of the hill that can supply 5 GPM at 90 PSI, or 208' of head. A pump can push water a long way, but can only suck water up 24' max, so putting the pump as close to the bottom as possible is best. I would also put a check valve on the discharge of the pump, not half way up the hill. A pump like a Goulds 5GB05 would work. You will either need to run wires from a float switch in the storage tank to the pump, or use a pressure tank/pressure switch to turn the pump on, and have a solenoid valve with float switch at the tank.
View attachment 48129

I see you mention 5GMP twice in your reply. If it makes any difference, I don't need 5GPM as a flow rate. I just need to replace what I use during the day, and that should be pretty minimal, depending on who's staying at the other house and how much water they use. Flow rate, if I understand your reference, is relatively unimportant to me as far as how fast the tank is refilled.

So, I guess my question is if I only needed a flow rate of say 3GPM, would the pump likely pump water further, allowing me to locate it further up the line, or am I thinking about this all wrong?

 

[Boycedrilling]

If you have line of sight to the reservior location, you could use a rangefinder with inclination indication. Like the Vortex Impact. $200 online.

If you have good topio maps you could estimate within 10 feet or so.

If you run the waterline first, you could fill it with water and read the psi at the bottom.

I would recommend that you use bigger diameter pipe than 1/2” though.

 

[Reach4]

So, I guess my question is if I only needed a flow rate of say 3GPM, would the pump likely pump water further, allowing me to locate it further up the line, or am I thinking about this all wrong?

I think the way to think about this is that you are going to use a 1/2 HP pump. What gpm pump will a 1/2 HP pump be efficient at raising to your elevated tank over the range of water pressures that you expect. For that, you will want to know the water pressure at the bottom (compensating for drop due to flow) and you will want to know the altitude change.

 

[PanamaJack]

If you have line of sight to the reservior location, you could use a rangefinder with inclination indication. Like the Vortex Impact. $200 online.

If you have good topio maps you could estimate within 10 feet or so.

If you run the waterline first, you could fill it with water and read the psi at the bottom.

I would recommend that you use bigger diameter pipe than 1/2” though.

I'll look into the rangefinder. Wonder, though, if the decline would need to be consistent throughout the hill to gauge properly or how it would adjust for incline changes. At the top of the hill the tank sits on a relatively level spot, for obvious reasons. Then it slopes down gradually for about 100 feet or so, then drops off pretty steeply for the remaining 500 feet or so.

I'll see if I can use Google earth or something for a topo map. Otherwise, probably hard to score one here. But that's a great idea.

What exactly would knowing the PSI at the bottom tell me? How would I use that to calculate how many horses my pump would be able to push?

 

[PanamaJack]

If you have line of sight to the reservior location, you could use a rangefinder with inclination indication. Like the Vortex Impact. $200 online.

If you have good topio maps you could estimate within 10 feet or so.

If you run the waterline first, you could fill it with water and read the psi at the bottom.

I would recommend that you use bigger diameter pipe than 1/2” though.

Also, the reason I went with a 1/2" pipe is the T at the road off the municipal supply is 1/2" off a 3/4" (hahaha) main. I figured that was my choke point anyway, so why go to a larger pipe on the other side of it? Could be flawed thinking. Been known for some of that...

 

[PanamaJack]

I think the way to think about this is that you are going to use a 1/2 HP pump. What gpm pump will a 1/2 HP pump be efficient at raising to your elevated tank over the range of water pressures that you expect. For that, you will want to know the water pressure at the bottom (compensating for drop due to flow) and you will want to know the altitude change.

Yes, I see your point. Getting altitude is proving to be somewhat critical if I want to have any hope of installing this pump inline to optimize it's efficiency. That being said, with your help and the other help I've received here so far, I might just cowboy it in there and see what happens. I'm pretty sure the pump will push the water from somewhere in the line. I just don't know where to locate it to make sure it fills the tank (even slowly that's OK) and it doesn't push the limits of the tank.

Thanks for your thoughts and ideas.

 

[Valveman]

For every 2.31' in elevation you will see 1 PSI at the bottom. If the pipe is already in place, put a pressure gauge at the bottom and fill the pipe with water. If the gauge at the bottom reads 100 PSI, you know there is 231' of elevation. 50 PSI would be 115' an so on. It won't matter if the hill is steep or shallow, goes up and then back down, the pressure at the bottom will give you the exact elevation.

The longer the pipe and the higher the flow rate, the larger the pipe needs to be. At 5 GPM you will lose 48 PSI in 600' of 1/2" pipe on top of the elevation changes. But at 1 GPM there is very little friction loss in 1/2" pipe, so all you would have is elevation. As long as the pump can lift enough to handle the elevation, the flow rate will equalize with the friction loss, and you will just get what you get.

Figure out the elevation or pressure at the bottom, give us the pump model number or a link, and we can tell you if it will work.

 

[Boycedrilling]

When calculating how far or how high a pump will pump water, we calculate what is called TDH, total dynamic head. It has three components.

The first one is fixed and doesn’t change, it is the elevation or height difference. Every 2.31 feet of elevation equals 1 pound of pressure. If you were to take a pipe and run it 231 feet of elevation difference up a hill, you would have 100 psi on the pipe at the bottom of the hil. With a submersible Pump in a well, this the water level in the well, while the Pump is running, not the depth the Pump is set at.

The second components is the discharge pressure we desire. We convert that pressure to feet of head. So if we want 50 psi, we multiply the pressure by 2.21 and arrive at 115.5 feet of head.

The third component is the most variable. It is friction loss in our pipelines. The more water we try to push or pull through a pipe, the greater the friction loss. Normally we consult friction loss charts that have already done the Hazen-Williams friction loss calculations. These charts tell us for a specific pipe diameter and material, and for a specific flow rate, what the friction loss will be in feet of head per 100 feet of pipe. There are also charts for associated fittings that tell us for a specific fitting, the equivalent length of straight pipe. We also want to keep our velocity of water in the pipe at 5 feet per second or less.

These three components make up our Total Dynamic Head,. Then we can determine the appropriate Pump for the conditions.

So let’s pick some numbers. Let’s say we want to pump water up 100 feet. Doesn’t mater whether that up a hill or from 100 feet underground. Then we want to deliver that water at say 50 psi. We already calculated that as 115.5 psi. So now we have 215.5 feet of head to push water up a pipe and pressurize it to 50 psi, at NO flow. Our last step is to consult the friction loss charts and see what size pipe we need to deliver the flow of water we want. All at a reasonable amount of friction loss. So using the initial example we will use 5 gallons per minute, in a 1/2” pipe, 600 feet long. For PVC 1/2” pipe we have 22.2 feet of friction loss per 100 feet at 5 gpm. A total of 133.2 feet of head. So to deliver 5 gpm at the end of our pipe at 50 psi it takes (100+115.5+133.2) 348.7 feet of total dynamic head.

If we were to change the 1/2 pvc pipe to 3/4” pvc pipe out friction loss at 5 gpm would drop to 5.66 feet per 100 feet of pipe. A total of 34 feet of head. Now our TDH has dropped to 249.46 feet. We have saved 100 ft of head required by increasing the pipe from 1/2” to 3/4”.

 

[PanamaJack]

For every 2.31' in elevation you will see 1 PSI at the bottom. If the pipe is already in place, put a pressure gauge at the bottom and fill the pipe with water. If the gauge at the bottom reads 100 PSI, you know there is 231' of elevation. 50 PSI would be 115' an so on. It won't matter if the hill is steep or shallow, goes up and then back down, the pressure at the bottom will give you the exact elevation.

The longer the pipe and the higher the flow rate, the larger the pipe needs to be. At 5 GPM you will lose 48 PSI in 600' of 1/2" pipe on top of the elevation changes. But at 1 GPM there is very little friction loss in 1/2" pipe, so all you would have is elevation. As long as the pump can lift enough to handle the elevation, the flow rate will equalize with the friction loss, and you will just get what you get.

Figure out the elevation or pressure at the bottom, give us the pump model number or a link, and we can tell you if it will work.

Excellent! I will do that and post my findings. Thanks again for taking time to respond with such easy to digest information.

 

[PanamaJack]

When calculating how far or how high a pump will pump water, we calculate what is called TDH, total dynamic head. It has three components.

The first one is fixed and doesn’t change, it is the elevation or height difference. Every 2.31 feet of elevation equals 1 pound of pressure. If you were to take a pipe and run it 231 feet of elevation difference up a hill, you would have 100 psi on the pipe at the bottom of the hil. With a submersible Pump in a well, this the water level in the well, while the Pump is running, not the depth the Pump is set at.

The second components is the discharge pressure we desire. We convert that pressure to feet of head. So if we want 50 psi, we multiply the pressure by 2.21 and arrive at 115.5 feet of head.

The third component is the most variable. It is friction loss in our pipelines. The more water we try to push or pull through a pipe, the greater the friction loss. Normally we consult friction loss charts that have already done the Hazen-Williams friction loss calculations. These charts tell us for a specific pipe diameter and material, and for a specific flow rate, what the friction loss will be in feet of head per 100 feet of pipe. There are also charts for associated fittings that tell us for a specific fitting, the equivalent length of straight pipe. We also want to keep our velocity of water in the pipe at 5 feet per second or less.

These three components make up our Total Dynamic Head,. Then we can determine the appropriate Pump for the conditions.

So let’s pick some numbers. Let’s say we want to pump water up 100 feet. Doesn’t mater whether that up a hill or from 100 feet underground. Then we want to deliver that water at say 50 psi. We already calculated that as 115.5 psi. So now we have 215.5 feet of head to push water up a pipe and pressurize it to 50 psi, at NO flow. Our last step is to consult the friction loss charts and see what size pipe we need to deliver the flow of water we want. All at a reasonable amount of friction loss. So using the initial example we will use 5 gallons per minute, in a 1/2” pipe, 600 feet long. For PVC 1/2” pipe we have 22.2 feet of friction loss per 100 feet at 5 gpm. A total of 133.2 feet of head. So to deliver 5 gpm at the end of our pipe at 50 psi it takes (100+115.5+133.2) 348.7 feet of total dynamic head.

If we were to change the 1/2 pvc pipe to 3/4” pvc pipe out friction loss at 5 gpm would drop to 5.66 feet per 100 feet of pipe. A total of 34 feet of head. Now our TDH has dropped to 249.46 feet. We have saved 100 ft of head required by increasing the pipe from 1/2” to 3/4”.

Wow...ok! Thanks for the very detailed instructions on how to calculate the total head. I'm honored that you and the other responders on this forum took the time to give such easy to understand, and use, instructions.

Thanks again! What a great resource, this forum!