Water Line Size

Well I bought me a double wide and I've got the septic permit and it's been drawn out. I'm waiting on the house permit now then they'll deliver it. I've decided to hook onto the city water verses digging a well as the well will cost around $15,000. The city will put in a meter with a 1 hookup for $2,575. I'm trying to figure out what size pipe to use. I'll be going about 1100 or so feet up hill. Anybody know what to use? I thought about running 2 for 400' then 1 1/2 for 400 and 1 for the last. Would that be big enough to have good water pressure? What do you guy's think? Thanks for any help. Oh and to keep it tractor related I'm using my ford 3000 and single bottom plow to dig the trench.
 
Steve@advance is very correct. The volume through a one inch opening will supply enough water for 2 normal homes. The rate of flow is pressure dependent. You can work this out with a simple rule: 1 foot of water creates 0.433 psi of pressure, and it takes 2.31 feet of water to create 1 psi of pressure. This can be calculated for your total rise into this formula. We don't know the number. The distance is a factor in pressure loss with high flow rate, but you will not have that issue due to the one inch pipe capacity. The tap they install will certainly not have a 2 inch diameter opening!! So the restriction right there would negate the use of the bigger pipes than needed. Jim
 
I don't know where you live.
I bury my water lines 3 to 4 ft to prevent freezing.

I think the vertical distance is more important than the size of the pipe. Every 28 inches height you will lose 1 psi.
 
2.3 feet of elevation is 1 pound per square inch. You will need to know pressure at main, feet of elevation difference to point of use and flow requirements (gallons per minute) to be able to get an idea of what you need. Note few fixtures are over 1 1/2 gallons per minute, exceptions are requirements like filling a swimming pool ect..
 
Going larger than the city tap will gain nothing! But lose money in the larger pipe!
I would spend the money on the well. The city will raise the price for water every year and if you forget to shut off the water, you can end up with a thousand or two water bill!
 
With that distance I, 1 inch would be the minimum. If you can afford the cost put in a 1 1/2 or 2 inch. The friction for that distance will cause low flow issues for 3/4 inch..
 
Run 2 inch the whole way. This is a one-time expense, and you can't go too big.

If you're required to install a pressure regulator, make sure it's at the double-wide.
 
On one of the farms I bought I had to run a buried water line and used one inch BIG MISTAKE as once the trench is dug its not much more expensive to run larger resulting in less pressure drop across the line. WHEN AT IT I WOULD GO AHEAD and run the largest size and NOT have to mess with the smaller size adapters (more chances of problems with all the splices connections and adapters) to save a few bucks. I bet you will be glad you did for years n years only for a few more bucks. I spread a layer of sand on top and bottom of the line along with some warning tape.

YOUR money YOUR choice !!!!!!!

John T
 
MarkB made a good point about a pressure regulatory. Some public water systems the pressure can vary. Can get up to 125 psi or more. Plumbing fixtures are expensive and don't like pressure above 60 psi. They may not last.

My 2 inch recommendation is not about pressure or pressure drop. It's more when say a washing machine solenoid valve closes you have a good shock spike in pressure. The 2 inch would help. On my project I didn't want to dig a 1200 foot ditch again with the backhoe.
 

The average single family home needs 6.5 GPM to be able to supply all uses. If you use one inch poly pipe at 7 GPM you will loose .47psi/ 100 ft or 5 lbs total. This means that if the town puts in 65 lbs at the street you will get 60lbs with most of your taps open. It will be an unnoticeable loss. Pressure loss due to elevation is completely independent of flow. It is 4.33lbs/ ten feet of rise. So if the rise is 20 feet you will lose 8.7 lbs. Which again if you are running multiple taps you will be down to 55lbs. which looks like plenty to me. So unless you plan to run a laundromat or open a car wash one inch would be plenty.
 
My water line is 3050 feet and run in 1inch pipe. Its been like this since 1985 and Ive always had plenty of water. If the city meter is like mine its only 1/2 inch Id. Tony
 
> If you use one inch poly pipe at 7 GPM you will loose .47psi/ 100 ft or 5 lbs total. This means that if the town puts in 65 lbs at the street you will get 60lbs with most of your taps open. It will be an unnoticeable loss.

Hmm. Are you sure?

Using the pressure drop calculator below, I come up with 17 psi pressure drop over 1100 ft at 7 gpm, using 1 inch schedule 40 pipe. That's noticeable.

Going up to inch and a half reduces the pressure drop to 2 psi, and of course it's negligible with two inch pipe.
Water pressure drop through piping
 
> The tap they install will certainly not have a 2 inch diameter opening!! So the restriction right there would negate the use of the bigger pipes than needed.

Jim, I don't think that's a true statement over 1100 feet. Assuming a 3/4 inch tap, which I think is typical, you'll need much bigger pipe than the tap to avoid pressure drop over the length of the line. Maybe not 2 inch, but certainly 1-1/4 or more.
 
I am manager of a rural water system and we would NEVER use 1 for that length of line. Use 1 1/2 or 2. We have over 100 psi in our main lines with a pressure reducing valve to drop it to 55 or so psi.
 
(quoted from post at 17:08:35 05/23/22) > If you use one inch poly pipe at 7 GPM you will loose .47psi/ 100 ft or 5 lbs total. This means that if the town puts in 65 lbs at the street you will get 60lbs with most of your taps open. It will be an unnoticeable loss.

Hmm. Are you sure?

Using the pressure drop calculator below, I come up with 17 psi pressure drop over 1100 ft at 7 gpm, using 1 inch schedule 40 pipe. That's noticeable.

Going up to inch and a half reduces the pressure drop to 2 psi, and of course it's negligible with two inch pipe.
Water pressure drop through piping


Hmm, Yes I am sure using the parameters as I gave them please read again.
 
Well, I think I'd need some more details, and perhaps do some price checking to decide.

I take it 1100 feet is the span length, and not the elevation change. What kind of elevation change are you talking? Are you talking 25 ft. of upward elevation change, or 125 ft.???

Also, how far down is the city going to neck it down at the meter?? Does (a 1 hook up) mean they are necking it down to 1 inch at the meter? Or does that mean they are installing 1 meter (as in, you are not opening up a trailer park, with several meters and hook ups)??

To me, it doesn't make much sense to hook onto 1 inch line at the meter, and go back out to 2 inch.

It also doesn't make much sense to me, to install smaller pipe, if it's not going to cost that much more to install a one size bigger pipe.

In my opinion, if your going to do a neck down, after neck down, after neck down as you go along through the span, you might as well just do all the neck down in one step right where you leave the meter. The only way I'd mess with doing such neckdowns, is if you were going to go aways and put in a hydrant, and then go aways and put in another hydrant, and then go a ways and be at the house. Then I'd consider doing a neck down after I passed a hydrant, or some other hook on to the line such as a plumbing to an out building, or whatever. If no hook ons from point A to B, and there never will be, I'd forget the neck downs along the way in the trench.
 
A number of folks who ought to know better seem to think there's no point in using a larger pipe diameter than whatever the size of tap coming out of the main is. That is most certainly not the case. If that was the case, I'd be able to run my garden sprinkler, which has an output orifice that's about an eighth of an in in diameter, using an eighth inch line. In fact, I can't get by even with 5/8 inch hose; I have to use 3/4 inch hose because the garden is about 150 feet from the house and there's too much pressure drop using 5/8 inch hose.

If you go too small on your water line, it won't matter if the tap at the main is 3/4 inch, one inch, or six inches, because the undersized pipe will restrict flow below what can pass through the tap.

Also, there's no reason to reduce your pipe size as you get closer to the house. Keep the pipe size the same the full length. If you don't think you need 2 inch for the full distance, just run one and a half inch the whole way.
 
(quoted from post at 03:09:21 05/24/22) > Hmm, Yes I am sure using the parameters as I gave them please read again.

How are you calculating the pressure drop? I tried a different calculator and came up with 20 psi this time. Again, that's 1100 feet of 1 inch ID pipe at 7 gal/min.
A different pressure drop calculator.

Mark, I expect that the difference is most likely due to the flow value. We fire service pump operators are required to understand the relationship between flow rate and friction loss. I used friction loss tables of Hunter Industries, they are an irrigation supply company. I agree that it is strange that so many think that flow of a liquid is limited by any small diameter part of the over-all installation.The situation is simply that friction loss, which is what reduces the flow, is a function of distance. If the length is insignificant with respect to the whole installation so will the pressure drop be insignificant. Liquids are flexible. The flow will bend around corners. It will flow just a little faster through a restriction and then speed right up again. If it is necessary to have a larger diam. pipe than the calculations call for why not two inch? why not four inch? Why not twelve inch? It will be expensive to go back and replace the four inch pipe with twelve inch.
 
I like to use the analogy of how VOLTAGE (water pressure) drops as CURRENT (CFM of water flow) flows through a RESISTANCE (smaller pipe = more resistance to flow) ... Just as Voltage drop = I x R Pressure Drop across a pipe is flow (CFM) X resistance. Voltage drops as current flows through a wire just as pressure drops as water flows through a pipe and smaller pipe = more resistance to flow

SOOOOOOOOOOOOOO bigger pipe still = less voltage drop REGARDLESS if there were a small restriction at say the meter where it goes out the pipe to the house.

Using bigger line reduces line pressure drop REGARDLESS if there was a 1/2 or 1 inch or whatever at the meter. Use what you like but the FACT remains bigger pipe = less pressure drop

Thats my story n Ima stickin to it lol

Best wishes everyone take care be safe be happy

John T
 
> Mark, I expect that the difference is most likely due to the flow value. We fire service pump operators are required to understand the relationship between flow rate and friction loss. I used friction loss tables of Hunter Industries, they are an irrigation supply company.

OK, I found those tables and I see that the calculators that I used must be using a much higher friction loss value. I didn't realize how much the friction varies between different kinds of pipe.
Hunter friction loss charts PDF
 
Thanks for all of the comments and help. As far as getting another price for the well everyone is around $55.00 per foot and the wells around there range from 2 to 0ver 3 hundred feet that's a lot of money. As far as asking the city the man said run 1 it'll be fine. My best friend's good friend was over the same water department for 5 years and I got him to ask him and he said run 1 all the way and hope you have enough pressure. They didn't sound to sure of them selves. And this city isn't the best at anything. My thinking was if I use a bigger pipe then there would be more water in the lenght so the pressure would have a good supply of water to push. Also around here if the pump goes on a well your looking at around $4,000.00 to replace it. Everything to do with a well around here in Fayette Co. Tn is lots of money. Also if the power goes out no water. The guy my friend asked said if I didn't have good pressure I could add a booster pump at the house. I'm trying to be as cost effective as possible after my wife died last October it's only my salary and I've only got a set amount of money to spend. Again thanks for all of you help. God bless.
 
> My thinking was if I use a bigger pipe then there would be more water in the lenght so the pressure would have a good supply of water to push

It's not the volume of water in the pipe, it's the friction of the water flowing through the pipe. Smaller pipe = faster velocity = more friction.

Two inch does seem like overkill. Inch and a half? Maybe overkill. One inch? Fuhgetaboutit.
 
If the line reduces the flow you could add a pressure tank at the house, that might not be a bad idea anyhow. Also you might need a booster pump if you are very much higher than the main, you loose .44 psi for every foot of rise.
 
(quoted from post at 06:04:13 05/24/22) If the line reduces the flow you could add a pressure tank at the house, that might not be a bad idea anyhow. Also you might need a booster pump if you are very much higher than the main, you loose .44 psi for every foot of rise.


I had a restaurant customer that was very busy with around 125 seats. We were trying to get their dishwashing machine to work properly. when they got into their rush the rinse water flow was too weak. The line coming to the building was only 3/4 inch. and it ran under US route 1. The state wouldn't let them dig the road up to put a bigger line in. Finally I got them to add another bladder tank to the 100 gal tank that they already had. That took care of it. They would often serve over 200 at lunch time. How many will you serve Danny?
 
There's 5 of us going to be living in the house with 2 bathrooms, washer etc. the line will start at the meter go down hill then up hill if I go across my pond dam it would be level for about 300 feet then uphill the last 500 give or take. I don't want to have to redo anything is why I thought of using bigger pipe. I can always add a pump at the house to help with the pressure if needed I'd just rather not.
 

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