# What size and kind of service line? help !!!



## mebedave (Feb 2, 2010)

I’m not a plumber (I’m a foundation repair contractor) so I’m looking for some plumbing advice. I live out in the country, here in Kansas. Water dept. is about to run a water line down my road and I’m going to switch over from my well. I need some help on what size service line, type of material I should use, and installation pointers. 
The 2” main line that’s branching off down my road to my property line is coming from up the road 1400 feet to a 6” line and that 6” line goes up to a new pump station ½ mile away. From where they set the water meter at my property line I need to run a service line to my house that’s apox. 700 feet away. I’ll be installing and trenching myself.

Here are some of the questions I have that I can think of:


What kind of pipe and connectors should I use or not use (money is an option!!)


What size service pipe should I use not to overkill but I would like to have good water pressure. My house is in all copper built in 1993 


I’m not yet sure what size meter they will be providing, question is, would there be any advantage as an example lets say they set a ¾” meter but I install a 1 ¼” service main. I’m not saying this is the case, I just want to know is running a larger service than the meter size helps me any.


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## UALocal1Plumber (Jun 19, 2009)

Larger service size will reduce pressure loss from tap to service valve. 

2" pipe 700' away? You can't expect much at the point of use.

Run a 1" soft temper, flared copper line from the tap to your meter. Install a pressure booster pump at the service entrance, it'll act as a surge tank as well as a pressure booster so that your pressure and volume needs are met.

Out in the country, you may be able to decrease your cost if you run the service in plastic. I don't have much experience with it, so someone else can tell you the right material. 

Make sure to stay below the frost line, and lay the pipe in soft fill.

Keith


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## UALocal1Plumber (Jun 19, 2009)

BTW what would you do to a hollow CMU foundation wall that's showing a lot of cracks at the mortar joints? Replace individual blocks? Add mortar, flat ties, dowels to reinforce? Thanks

Keith


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## mebedave (Feb 2, 2010)

UALocal1Plumber said:


> BTW what would you do to a hollow CMU foundation wall that's showing a lot of cracks at the mortar joints? Replace individual blocks? Add mortar, flat ties, dowels to reinforce? Thanks
> 
> Keith


 
Install 4" I-beams about every 4 foot and Repair the mortar joints. This will hold the wall inplace.


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## sprinklertech (Sep 15, 2009)

mebedave said:


> I’m not a plumber (I’m a foundation repair contractor) so I’m looking for some plumbing advice. I live out in the country, here in Kansas. Water dept. is about to run a water line down my road and I’m going to switch over from my well. I need some help on what size service line, type of material I should use, and installation pointers.
> The 2” main line that’s branching off down my road to my property line is coming from up the road 1400 feet to a 6” line and that 6” line goes up to a new pump station ½ mile away. From where they set the water meter at my property line I need to run a service line to my house that’s apox. 700 feet away. I’ll be installing and trenching myself.
> 
> Here are some of the questions I have that I can think of:
> ...


I am a little late on this but I love this sort of stuff.

Use the Hazen-Williams formula you can find it *here*.

If you aren't used to it before your eyes glaze over it isn't that bad.

Let's figure for 20 gpm which is a LOT of water.

Taking the meter first the size isn't going to matter that much. A 5/8" *Hersey 400 series* meter (page 2) produces a head loss of 5.5 psi @ 20 gpm and seeing as how a 3/4" meter produces 2.2 psi upsizing the meter isn't going to be worth the added cost and possible capacity charge. In some locations the excess capacity charge can add a lot onto your bill every month even if you don't use that much water.

For underground you will probably use a plastic which is fine. The friction loss coefficient (C-value) of both copper and plastic is th same at 150 so I would go with plastic it being a lot cheaper.

Now all we have to do is compare the friction loss from the meter to your house for different diamters of pipe. For simplicity sake we'll use nominal diamters which will get us close enough.

The friction loss flowing 25 gpm through 3/4" plastic is 0.67 psi/foot or a whopping 469 psi so 3/4" is out of the question. To small.

The friction loss flowing 25 gpm through 1" plastic is 0.165 psi/foot or a 115 psi so 1" is still to small.

The friction loss flowing 25 gpm through 1 1/4" plastic is 0.128 psi/foot or 89 psi so 1 1/4" is still to small.

The friction loss flowing 25 gpm through 1 1/2" plastic is 0.053 psi/foot or a 37 psi so 1 1/2" is still to small if you want 25 gpm.

*But I think every plumber here would agree 25 gpm is a lot for domestic water.* Contrary to what some might intuitively think if you double the flow it does not double the friction loss it raises it to ^1.85 power. For example when flowing 12.5 gpm through a 1 1/2" pipe the head loss developed will be .006 psi/foot or just 4.2 psi through 700' as compared to the 37 psi developed flowing exactly twice the water.

The friction loss flowing 25 gpm through 2" plastic is 0.006 psi/foot or 4.2 psi over the 700' length. Interesting if you lower the flow to 20 gpm (probably more than adequate) the head loss drops to .004 psi or just 2.8 psi over the entire length.

I think you will find the cost between 1 1/2 and 2" is very small. 1 1/2" is harder to get and I have a feeling it isn't unlike me trying to purchase 3" cement lined DI water main as opposed to 4". The 4" is actually cheaper.

Another approach to take would be to accept most house taps are 3/4" copper and might run 75' from the city water main to the house. Find a pipe size that approximates the head loss developed through 75' of 3/4" pipe say flowing 10 gpm. @ 10 gpm that is 21.3 psi. Through 700' of 1" the loss would be 48.94 psi which would indicate to me 1" is to small being over double what 75' of 3/4" would be. Using 1 1/4" the loss would be 16.5 gpm which is actually a little less than the 75' of 3/4".

Most likely 1 1/4" would do the trick but to bumping it up to 1 1/2" wouldn't hurt. The last thing you want to do is undersize, be unhappy with the pressure from the shower and have to add a booster pump with electric etc ending up with a lot more expense than if you simply had upsized the pipe.


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## mebedave (Feb 2, 2010)

_Sprinklertech Thank you for the info (your late but not to late water dept is just now trenching for the water to my house) this info you gave me has helped me a lot to understand and I think I will go with 2". Now I must decide what kind, pvc, ploy,pex, rating, class etc... driving me crazy any input here...Thanks_


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## TimelessQuality (Sep 23, 2007)

PVC is pretty standard for service entry, in my area.. but I would check with RWD to see what they recommend

20 footers, bell end, should go quick....

Where in the state are you? I'm just north of Wichita.

Stop by the intro section and lets know a little about your business...Thanks!


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## Williams Ex Co (Dec 25, 2007)

I would agree with TimelessQuality that 2'' gasketed pipe would make this go pretty quick and easy. Knock 'em together on top and feed the assembled line in directly behind the trencher... Dont trench the whole line and figure on throwing the pipe in later, you may say a 4 letter word or two when you find the spot that caved in on the trench.... Ask me how I know!


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## sprinklertech (Sep 15, 2009)

mebedave said:


> _Sprinklertech Thank you for the info (your late but not to late water dept is just now trenching for the water to my house) this info you gave me has helped me a lot to understand and I think I will go with 2". Now I must decide what kind, pvc, ploy,pex, rating, class etc... driving me crazy any input here...Thanks_


I think that is a wise decision. You can't go wrong going with 2" you'll have more water pressure available at the sink, faucet or shower head than before. Given the 700' length I have no doubts the 3/4" and 1" is woefully undersized and you wouldn't be happy with the shower performance using either. The 1 1/4" probably as well but 1 1/2" and 2" probably isn't. Given the price difference between 1 1/2" and 2" for the extra pennies (if that much) go for the 2".

I don't use the stuff but looking at US Plastics I find 1 1'2" selling for $92.85/100'(100 psi) while 2" sells for $154.64/100'(100 psi). $432.53 extra to go with 2". I am sure it is more than you want to spend but you are already paying for so much. If times are really tight I would go with the 1 1/2" to save the $432.53 but would not go to the 1 1/4". Oh, with buying a quantity of more than 4 you get a 10% discount so it's $83.56 for 1 1/2" and $139.18 for 2". Not to bad.

Every fixture has a coefficient of discharge and we can demonstrate this with the lowly yard sprinkler attached to the end of a garden hose. This is something we have all observed.

We will call the coefficient of discharge the 'k-factor" just to make it easy.

Let's attach a twirling yard sprinkler onto a short piece of 3/4" hose but right where male end of the hose connects to the sprinkler we'll insert a short piece of pipe with an outlet for a water gauge.

We turn the sprinkler on and observe the pressure while collecting all the water in a 20 gallon garbage can. The pressure at the sprinkler connection is 16 psi and it takes us 10 minutes to fill the garbage can. This is *2.0 gpm flowing*.

The coefficient of is found by applying the formula k=q/p^.5 where q=water in gpm, p=pressure in psi and k=coefficient of discharge.

k=2.0/16.0^.5
k=2.0/4.0
k=0.50

Now that we have the discharge coefficient we can determine what the discharge would be at any pressure. This is where it gets interesting because just because you double the pressure to a device; yard sprinkler, shower head or faucet, does not mean a doubling of the discharge.

Let's say the faucet on the hose feeding our yard sprinkler was partially closed and by fully opening it we noted the pressure gauge jumps from 16.0 psi to 32.0 psi and it is obvious more water is flowing but how much?

Is it double since the pressure doubled?

No.

q=k*p^.5
q=0.50*32.0^.5
q=0.50*5.65
q=2.82 gpm

So we doubled the pressure at the yard sprinkler which resulted in the discharge increasing from 2.00 gpm to 2.82 gpm which is hardly double. My message to the plumbers out here is don't go doubling something thinking you are going to get something double out because you won't.

Cool, huh?

So what kind of pressure would it take at the pressure gauge to double the water to 4.00 gpm?

p=(q/k)^2
p=(4.00/0.50)^2
p=8.00^2
p=64.00 psi

The pressure will have to be raised from 16 psi to 64 psi (*4 times as much*) simply to double the quantity of water being discharged.

So given this information what happens if we plug in 100' of 1/2" hose to water the back of the garden? We know from experience the sprinkler won't act as well, we won't have as much water but what is going on?

Assume 2 gpm flowing through 100' of 1/2" hose. Using the *Hazen-Williams Calculator* it is determined the head loss through the additional 1/2 hose is 4.5 psi meaning if we can maintain the 16.0 psi at the point where the sprinkler 'was' attached before we added the 100' of hose, we will have 4.5 psi less pressure at the sprinkler head.

At 11.5 psi, instead of 16.0 psi that that gave us a discharge of 2.0 gpm, the same lawn sprinkler will but out q=0.50*11.5^.5 or 1.7 gpm instead of the 2.0 gpm we had before.


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## mebedave (Feb 2, 2010)

Sprinklertech Thanks for that crazy info  I think I'll change your name to Dr. Water..... 

I'm leaning to 20' glue up bell end 2" pvc at this point, any advice I'll take it.

Thanks


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## Williams Ex Co (Dec 25, 2007)

I wouldnt use the glue/bell end pipe. Better off with gasketed pipe as it allows for a bit of flexing in the joint if need be... flex a glued joint much and it breaks the solvent weld.


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