Replacing old galvanized water supply line from meter to entry at house

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K9mlxj

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I replaced mine almost 25 years ago, and used 1" PVC 18" down. 20' is under the driveway...


Here's something I don't understand. I checked my water bill and it states "Rate Code /Service Size : RES_T_B 3/4 inch".

But the connecting old galvanized pipe (from the house) size to the meter is 1" diam. When it comes out of the concrete it's reduced to 3/4" when connecting to the copper pipe from the house.

Main - old galvanized pipe size.jpg


I called the water company and the lady just followed my account profile and said I needed a 3/4" pipe connecting to the meter.

But I wonder about the reason the Service Size states 3/4" when the galvanized connecting service pipe size is 1"?



I would put it in an 4" ABS sleeve, so you can change/add pipes.

An ABS sleeve -- for the whole length of the service line from the meter to above the concrete by the house?
 
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Terry

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If you have a two or three bath home, you should have a 1" service to the home with your 3/4" meter.
Only if you have a one bath home would a 3/4" service make any kind of sense.
The larger pipe size reduces friction at very little cost on the upgrade, which is noticeable to the homeowner when the plumbing fixtures are used. It's better to oversize a service then to undersize it. If you have two baths, then 1" is the correct size.
 

Terry

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Water pipe sizing

Have you looked at this page yet?
It has a chart from the code book explaining pipe size. We don't have to reinvent anything, this stuff is old news.
Water meters used to be 5/8", and then in the last few decades, or maybe I should say, in the last 60 years they were 3/4".
You can pass a lot of water through a 3/4" meter and setter.
After that, you need to worry about friction loss. The longer the tubing is, the more loss you have. Think drinking a pineapple shake through a coffee stirrer.
We also can't use 1/2" PEX for a tub spout with diverter. It's so small it pushes water upward to the shower head in the "tub" position.

Friction loss determines pipe sizing. The longer the pipe, the less water that can go through it.

Copper Pipe at 80 feet with a 3/4" meter and setter.
1/2" pipe, 6 units
3/4" pipe, 19 units
1.0" pipe, 36 units

A bathroom with a tub, toilet and lav is 7.5 units
The cold requires 3/4". The hot needs 1/2"
 
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Jadnashua

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Over a short distance, when you reduce the pipe size, the water just speeds up through that short section and slows back down again when the pipe gets bigger, maintaining the volume. It becomes a big issue when the restriction is long, then it cannot recover, or the velocity gets higher than you want and can erode the piping.
 

K9mlxj

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I get that I'd need an oversized 1" pipe. I suppose the statement in my water bill "Rate Code /Service Size : RES_T_B 3/4 inch" only means the 'minimum required' pipe size for the meter then.


Also I still wonder about the 4" PVC sleeve over the copper pipe. Sound good idea in case I need to replace pipe in the future. Is this option practical in CA though (earthquake prone area)?


If I add a 4" PVC sleeve over the 1" copper tube do I run it thru' the whole length incl. above ground (and how do I avoid dirt from getting in from either end of the sleeve)? I wonder the right way to run this sleeve.


Here's a related article: http://www.inspectionnews.net/home_inspection/questions-home-owners-home-buyers-diy/22942-insert-copper-pipe-water-main-into-polyvinyl-chloride-pipe.html


The article also mentioned an 'auxiliary chase'. Perhaps someone can enlighten me a bit about the usage of this.


Thx.
 
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Cacher_Chick

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3/4 is the meter size. Many water utilities base your fee off the size of the meter and the actual water usage.

I would sleeve the pipe only where it goes under the slab.
 

Wet_Boots

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I've seen similar construction in some homes in the North Bay area. There may not be any particular need to bring the replacement service line to the point where it currently enters the home. Instead, you would pick an entry location where you don't have to break up any concrete, and do the necessary plumbing in the crawl space to make the new connection complete (you DO have crawl space access, don't you?)

This method would also have the advantage of being doable with the current connection in place.
 

K9mlxj

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Someone says the copper pipe should not be in touch with concrete as concrete eats copper.

Is that true?

So then I wonder where the copper pipe goes into the concrete box for the water meter --

should I sleeve that spot where the copper pipe goes thru' the bottom of the concrete box, or I can just tape around the copper pipe to shield it off from the box?

Also, soldering on the soft copper tubing is ok?


I plan to put in sleeve in the area that is under the slab, including the L that leads up to the slab surface where the house entry is. Is it good to drill a few holes at the bottom of the sleeve (particularly around the vertical L turn) so to let water drain out?
 
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Craigpump

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Is copper required by code?

Not only is copper expensive, but it will corrode if the surrounding soil has a low pH just like it will if it comes into contact with cement. I would use 160 or 200 psi poly if the local inspectors will accept it. The poly is a lot cheaper & easier to work with too.
 

K9mlxj

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Above ground soldering should be ok for soft copper tubing? I guess I need to tape/sleeve the copper tubing where it goes thru' the concrete box/slab.
 

Wet_Boots

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Frankly, you are way overthinking this. From the photos you supplied, it looks like it is easy enough to bring in new service without messing with concrete and sleeves.
 

Terry

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If a galvanized water service is removed, the electrical panel must be grounded first

http://www.kirklandwa.gov/depart/Fi...ion_Guides/ELE_and_H2O_MIX.htm?PageMode=Print

Has the electrical panel been grounded after replacement of the water service?
Often, on a water service replacement, we make sure the main panel is grounded before any pipe is cut. If the panel was using the water service for a ground, you will need to add ground rods first.

Sometimes the panel is grounded to the water service.
 
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K9mlxj

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Thx I'm redoing the main electrical panel so would redo the grounding.


A question:

I'm thinking of possibly remodeling a few years later -- meaning I might need to move the water main entry location to the house to a different spot at that time.


Would that be ok to move the soft copper line later on -- e.g. bend the copper main water line at a different angle only, but no need to extend the length.
 
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Terry

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Would that be ok to move the soft copper line later on -- e.g. bend the copper main water line at a different angle only, but no need to extend the length.

If it's soft copper, you may be able to get a little bend out of it.
Copper gets stiffer each time it's moved.
 

Jadnashua

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Do yourself a favor and pound some ground rods. Yes, you can bond the water pipes to the grounding system, but water pipes themselves should not be the system ground point. If you haven't already run the new supply line, and can accept it coming from a different location where you don't need to go underneath the concrete, there's no reason you can't bring it into the house there, then run it to the old supply point inside of the house.
 

SteveW

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Frankly, you are way overthinking this. From the photos you supplied, it looks like it is easy enough to bring in new service without messing with concrete and sleeves.


To add to this observation, this thread is coming up on its two-year anniversary.
 
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