New drainage laterals, bad water main pipe discovered

[hallerb]

time to replace the remainder before it leaks and does damage

the improved pressure and flow may lead to other faster failures

[BobK207]

Dan-

Here is a link to a pressure drop table for copper tubing as long as the flows through your mainline are reasonable

[Everett M. Greene]

I just discovered (after 15 years) that I've been paying a premium to the water district for the privilege of having a 1" water meter (about $15/month more than a

3/4" meter). I don't know of any good reason for needing the larger meter since we don't use water for anything unusual. Would it be worth the trouble to make the change to the meter size? [It's no problem getting to the meter since our lines are so shallow (about 6" below ground).]

[Edwin Pawlowski]

It will save you $80 a year, and if you have 3/4" lines, the larger meter does no good.

[Dan_Musicant]

: :Dan_Musicant wrote: :> After the 3/4" water main was installed I am finding that my water :> pressure is very much improved. I don't notice it so much when using a :> tap or whatever. What I'm noticing is when I use more than one thing. :> For instance, I can flush the toilet and not have my shower lose 2/3 of :> its flow! It's a major improvement. The interior piping is still very :> old 1/2" galvanized almost entirely, but it appears that the old 1/2" :> galvanized water main was severely corroded, both on the interior and :> exterior. Well, whether it was interior or exterior, combined they were :> enough to make the pipe so fragile as to break in the first place, :> leading to the necessary replacement. :>

:> Dan : :time to replace the remainder before it leaks and does damage : :the improved pressure and flow may lead to other faster failures

Thanks! At the very least, I'll be keeping an eye on it. I can and should have a look at the meter occasionally to see if the dial is moving when it is not supposed to. That would be the easiest and only foolproof method of determining if there's a leak, seems to me.

Dan

[Dan_Musicant]

: :Dan_Musicant wrote: :> After the 3/4" water main was installed I am finding that my water :> pressure is very much improved. I don't notice it so much when using a :> tap or whatever. What I'm noticing is when I use more than one thing. :> For instance, I can flush the toilet and not have my shower lose 2/3 of :> its flow! It's a major improvement. The interior piping is still very :> old 1/2" galvanized almost entirely, but it appears that the old 1/2" :> galvanized water main was severely corroded, both on the interior and :> exterior. Well, whether it was interior or exterior, combined they were :> enough to make the pipe so fragile as to break in the first place, :> leading to the necessary replacement. :>

:> Dan : : :Dan- : :Here is a link to a pressure drop table for copper tubing as long as :the flows through your mainline are reasonable

[George E. Cawthon]

You need to find out what a change would involve. It may not be just the size of the meter that needs to be changed.

[Dan_Musicant]

:Everett M. Greene wrote: :> I just discovered (after 15 years) that I've been paying :> a premium to the water district for the privilege of :> having a 1" water meter (about $15/month more than a :> 3/4" meter). I don't know of any good reason for needing :> the larger meter since we don't use water for anything :> unusual. Would it be worth the trouble to make the :> change to the meter size? :> :> [It's no problem getting to the meter since our lines are :> so shallow (about 6" below ground).] : :You need to find out what a change would involve. : It may not be just the size of the meter that :needs to be changed. I just had my water main replaced and on recommendation first called the utility. They said I was on my own. I asked them what size the meter was and they said I had 5/8" at the meter. Some people have 5/8 some 3/4. I asked if they could change me to 3/4 and they quoted some ridiculous figure and forgot all about it.

If they'll change you to 3/4 without charging you (much) then you'd save $15/month, as you say. I'd imagine you'd not notice any change in your service other than smaller bills.

[BobK207]

[DK]

They will charge you a bloody fortune to change it, so keep your trap shut.

[Dan_Musicant]

:> Thanks Bob. I'm rubbing my chin on that one and trying to understand it. :> You forgot the link! :>

:> Dan : :

Ah, thanks. The subject is:

"Pressure Loss of Water Due to Friction in Copper Tubes"

My intuition on this is that the friction component using copper tubing (especially new) is going to be WAY less than my old rusty galvanized

1/2". Add to that the fact that the cross section of the interior of 3/4" pipe is 2.25 times that of 1/2" pipe, and you have MUCH better water flow and pressure. That's intuitive, of course. The linked page and it's table is based on engineering science.

Dan

[Everett M. Greene]

The District will not charge me anything but they will tell me that I'm responsible for everything past their meter. I had to replace the shutoff valve a couple of years ago when it started leaking around the stem. They gave me the valve but I was responsible for installing it. We replaced the meter at the same time since the District service guy said the previous one looked a little poorly.

[BobK207]

Your intuition is correct.......YEARS ago (1979) I was having the shower feeds in my 1930 house redone

I was so fed up with low water pressure I was going to make the plumber replace my 59 year old 1/2 galv with 3/4" cooper feeding first floor shower & then onto the 2nd floor.

I really water 3/4" copper the plumber talked me out of it....saying the "flow factor" of old copper tube is way better than new glav. I went with 1/2" copper.

Fast forward to 2007 & now I finally getting around to doing the rest of the house.

I'm going to use PEX w/ a home run system. I'm torn about replacing the perfectly still good copper but I may as well since the walls will be open.

The 16' run to 1st floor shower & the 26' run to second floor

Worst case with 125F hot water & 45F cold water (that's pretty cold) .....I'll need 1.5 gpm hot & .5 gpm cold to service a 2gpm shower

A run of 1/2" PEX 26' long will only drop ~1.8psi

My house is fed with 1" copper (~50' to the street) another 25' of 1" PEX to the hot/cold split

1" feeding the cold manifold & 1" feeding the hot manifold

If I run the dishwasher (~2gpm) & two showers (2 gpm ea) I'll need ~6gpm to the house & 5 gpm hot water

The thing that causes problems is not only the pressure drop but the change in pressure drop as water demand increases or decreases. When you're taking a shower & you have the temp adjust you don't want significant increases or decreases in water pressure where you're using it....reduction is total pressure is annoying enough but when the hot or cold pressure changes alone...it can be more than annoying.

Unfortunately that table of copper tube pressure drops leaves a little to be desires wrt significant figures......only one in most of the entries :(

anyway if you play around with the numbers you'll probably find that a

3/4" line will supply most reasonable home usage without significant pressure drop.....unless you get the washer going, the dishwasher, two showers & a random toilet flushing.

But hey, I'm just happy if I can take a shower & not be bothered by one or two other water usages.

cheers Bob

[Wayne Whitney]

Bob,

Isn't 1" feeding the hot manifold overkill? The downside of oversizing hot water supply pipes is that you have to empty them every time you want hot water at a fixture. That's roughly true, as my experience has been that the period between hot water uses usually exceeds the cooling time of the water in the pipe, even if the pipe is insulated. Emptying the pipes wastes water (unless you have a point of use pump) and energy, the heat loss of the water that had been hot.

Just a thought.

Cheers, Wayne

[BobK207]

Wayne-

You are absolutely correct on that, 1" is way over kill for a supply to a normal house hot water manifold

Except in my installation the tube run from the WH to the manifold will be about 6' max. I didn't want to buy a roll of 3/4" just for that short run. The rest of my installation will be 1/2" (~500') plus about

20' of 1"

So I really don't need much 3/4 or 1". Got a source short lengths of

3/4" & 1" ? :)

cheers Bob

[Dan_Musicant]

:Dan_Musicant wrote: :> On 17 Jan 2007 23:34:25 -0800, "BobK207" wrote: :>

:> :> Thanks Bob. I'm rubbing my chin on that one and trying to understand it. :> :> You forgot the link! :> :>

:> :> Dan :> : :> :

:> Ah, thanks. The subject is: :>

:> "Pressure Loss of Water Due to Friction in Copper Tubes" :>

:> My intuition on this is that the friction component using copper tubing :> (especially new) is going to be WAY less than my old rusty galvanized :> 1/2". Add to that the fact that the cross section of the interior of :> 3/4" pipe is 2.25 times that of 1/2" pipe, and you have MUCH better :> water flow and pressure. That's intuitive, of course. The linked page :> and it's table is based on engineering science. :>

:> Dan : : :Your intuition is correct.......YEARS ago (1979) I was having the :shower feeds in my 1930 house redone : :I was so fed up with low water pressure I was going to make the plumber :replace my 59 year old 1/2 galv with 3/4" cooper feeding first floor :shower & then onto the 2nd floor. : :I really water 3/4" copper the plumber talked me out of it....saying :the "flow factor" of old copper tube is way better than new glav. I :went with 1/2" copper.

Today I had a look at the old water main shutoff valve that they cut out when they replaced the water main. On either side is galvanized pipe and on one side I could see rust that reduced the 1/2" internal diameter by at least a factor of 2. And that is just one spot. And the knobby rusty obstruction was clearly doing more than restricting flow by reducing the effective diameter. It was adding a tremendous amount of turbulence, which would very significantly reduce the gpm delivered to various sytems in my house. I'm contemplating replacing some of the interior piping, but I really have no good reason to do so presently. My pressures are good, at least partly because of the high pressure delivered to the house. I should probably actually have a pressure reduction valve where the main surfaces at the front of the house. A Plumber told me they are $100 and I believe they only reduce the psi by

5-7 psi. : :Fast forward to 2007 & now I finally getting around to doing the rest :of the house. : :I'm going to use PEX w/ a home run system. I'm torn about replacing :the perfectly still good copper but I may as well since the walls will :be open. : :The 16' run to 1st floor shower & the 26' run to second floor : :Worst case with 125F hot water & 45F cold water (that's pretty cold) :.....I'll need 1.5 gpm hot & .5 gpm cold to service a 2gpm shower

My requirements are different because I live alone. I envision selling the house, so the buyer's requirements will be greater than mine.

Myself, I have an on demand WH, which has a remote and I keep the temperature at the lowest, which is 100 degrees. When I take a shower, I push that to 110 in the summer and 115 in winter. When it's chilly, 115 delivers a perfect shower using hot water only. I guess that even if someone were to flush a toilet while I was taking a shower it wouldn't much affect the water temperature.

If you have a lot of people in the house, measures like mine aren't practical, obviously. You have constant hot water temperature and deal with it. : :A run of 1/2" PEX 26' long will only drop ~1.8psi : :My house is fed with 1" copper (~50' to the street) another 25' of 1" :PEX to the hot/cold split : :1" feeding the cold manifold & 1" feeding the hot manifold : :If I run the dishwasher (~2gpm) & two showers (2 gpm ea) I'll need :~6gpm to the house & 5 gpm hot water

I don't have a dishwasher yet. : : :The thing that causes problems is not only the pressure drop but the :change in pressure drop as water demand increases or decreases. When :you're taking a shower & you have the temp adjust you don't want :significant increases or decreases in water pressure where you're using :it....reduction is total pressure is annoying enough but when the hot :or cold pressure changes alone...it can be more than annoying.

I'm amazed that my shower flow doesn't appear to drop much AT ALL, when I flush the toilet now with my new water main installed. : :Unfortunately that table of copper tube pressure drops leaves a little :to be desires wrt significant figures......only one in most of the :entries :( : :anyway if you play around with the numbers you'll probably find that a :3/4" line will supply most reasonable home usage without significant :pressure drop.....unless you get the washer going, the dishwasher, two :showers & a random toilet flushing. : :But hey, I'm just happy if I can take a shower & not be bothered by :one or two other water usages.

That would be nice.

:cheers :Bob

[Wayne Whitney]

Use copper for the 3/4"? If you bump a pipe up from 3/4" to 1", assuming the ID is the nominal diameter (which it isn't), then for every one foot length of the increased size, the pipe takes 1 second longer to empty at 1.0 gpm.

Cheers, Wayne

[blueman]

I get 15*12= $180/year

[Edwin Pawlowski]

so did I, but the "1" key was not hit hard enough. I'll make up for it now.

1 1 1 1 1 1 1 1 1