I've got a basement full of old half-inch copper pipe, and some of it
needs to be replaced. I want to do repairs in 3/4" pipe but I'm
wondering if that will cause problems with the water changing pipe
sizes on its way to an outlet. Can I do this?

On Sun, 15 Mar 2009 15:21:37 -0500, Bert Byfield
wrote:

I've got a basement full of old half-inch copper pipe, and some of it
needs to be replaced. I want to do repairs in 3/4" pipe but I'm
wondering if that will cause problems with the water changing pipe
sizes on its way to an outlet. Can I do this?



Maybe. When I need to feed two appliances, I use 3/4", otherwise it
is 1/2".

Bert Byfield wrote:
I've got a basement full of old half-inch copper pipe, and some of it
needs to be replaced. I want to do repairs in 3/4" pipe but I'm
wondering if that will cause problems with the water changing pipe
sizes on its way to an outlet. Can I do this?





It will cause a problem if there are long runs on the Hot side.
3/4" pipe has roughly 50% more area than 1/2", meaning that
50% more volume of water has to be drawn from a distant faucet
before Hot water arrives. That may be trivial or it may be a
real pain in the neck.

On Mar 15, 3:14*pm, Speedy Jim wrote:
Bert Byfield wrote:
I've got a basement full of old half-inch copper pipe, and some of it
needs to be replaced. I want to do repairs in 3/4" pipe but I'm
wondering if that will cause problems with the water changing pipe
sizes on its way to an outlet. Can I do this?

It will cause a problem if there are long runs on the Hot side.
3/4" pipe has roughly 50% more area than 1/2", meaning that
50% more volume of water has to be drawn from a distant faucet
before Hot water arrives. *That may be trivial or it may be a
real pain in the neck.

OP-
Speedy Jim is on the right track about 3/4" vs 1/2" (both nominal
size copper tube) but unless my calcs are wrong...the 3/4" tube will
have closer to twice as much cold water volume to clear. This will
double your hot water wait time.

Why does the copper need replacing? acidic water? leaks?

I dont see why varying pipe size would otherwise cause problems.

cheers
Bob

I've got a basement full of old half-inch copper pipe, and some
of it needs to be replaced. I want to do repairs in 3/4" pipe
but I'm wondering if that will cause problems with the water
changing pipe sizes on its way to an outlet. Can I do this?

It will cause a problem if there are long runs on the Hot side.
3/4" pipe has roughly 50% more area than 1/2", meaning that
50% more volume of water has to be drawn from a distant faucet
before Hot water arrives. *That may be trivial or it may be a
real pain in the neck.

OP-
Speedy Jim is on the right track about 3/4" vs 1/2" (both nominal
size copper tube) but unless my calcs are wrong...the 3/4" tube
will have closer to twice as much cold water volume to clear.
This will double your hot water wait time.

Why does the copper need replacing? acidic water? leaks?

There is white crud coming out of some of the copper joints. What is
that? I expected green corosion instead. Should I replace all those
joints?

But my primary leak right now is where a water pipe has been touching
the conduit for the main house power for fifty years or so, and the
contact has caused a pinhole leak, of 5 or 6 gallons a day. I'm
looking at inserting a "universal pipe repair clamp" between the pipe
and the conduit, before I think about replacing sections of pipe.

I dont see why varying pipe size would otherwise cause problems.
cheers Bob

Thanks both of you. I'll have to look at how long the hot water runs
are.

Sounds like a good idea, to replace the white edged joints.
Use solder made for drinking water.

As to the pinhole. If it's what I think the patch thing
(rubber and a clamp) will also separate the pipe from the
girder, so it doesn't continue to wear.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Bert Byfield" wrote in message
. 97.131...

There is white crud coming out of some of the copper joints.
What is
that? I expected green corosion instead. Should I replace
all those
joints?

But my primary leak right now is where a water pipe has been
touching
the conduit for the main house power for fifty years or so,
and the
contact has caused a pinhole leak, of 5 or 6 gallons a day.
I'm
looking at inserting a "universal pipe repair clamp" between
the pipe
and the conduit, before I think about replacing sections of
pipe.

"Bert Byfield" wrote in message
. 97.131...

There is white crud coming out of some of the copper joints.
What is
that? I expected green corosion instead. Should I replace
all those
joints?

But my primary leak right now is where a water pipe has been
touching
the conduit for the main house power for fifty years or so,
and the
contact has caused a pinhole leak, of 5 or 6 gallons a day.
I'm
looking at inserting a "universal pipe repair clamp" between
the pipe
and the conduit, before I think about replacing sections of
pipe.

The white crud may just be surface corrosion. Clean it off, put a coating
like petroleum jelly on it and see if it comes right back. Or it may be
minerals from the water if in fact there is a tiny leak. If a leak, it will
start in one spot and spread, If corrosion, it usually goes around the
exposed solder.

As for the pin hole, fix it properly by cutting out a section and sweating
in a new one. Then be sure it does not contact the hanger again. Any sort
of rubber will do the job.

Bert Byfield wrote:
....
But my primary leak right now is where a water pipe has been touching
the conduit for the main house power for fifty years or so, and the
contact has caused a pinhole leak, of 5 or 6 gallons a day. I'm
looking at inserting a "universal pipe repair clamp" between the pipe
and the conduit, before I think about replacing sections of pipe.

All you need is a slip over coupling (one w/o the ridge in the middle)
expressly for the purpose.

Cut the pipe at the location of the pinhole, clean the ends (remember to
also ream the inside of the cut to get rid of burs), then slip the
fitting over, flux and solder. Done.

Then, as somebody else noted, fix the contact point so the two don't
touch in some fashion and it'll probably outlast you.

I'd not worry about the rest until actually had a demonstrable problem.
Like the above, unless you have something very corrosive in the water
or other problems, likely it will no longer be your problem when it
actually requires replacement.

--

Bert Byfield wrote:
But my primary leak right now is where a water pipe has been
touching the conduit for the main house power for fifty years or
so, and the contact has caused a pinhole leak, of 5 or 6 gallons
a day. I'm looking at inserting a "universal pipe repair clamp"
between the pipe and the conduit, before I think about replacing
sections of pipe.

All you need is a slip over coupling (one w/o the ridge in the
middle) expressly for the purpose.
Cut the pipe at the location of the pinhole, clean the ends
(remember to also ream the inside of the cut to get rid of burs),
then slip the fitting over, flux and solder. Done.
Then, as somebody else noted, fix the contact point so the two
don't touch in some fashion and it'll probably outlast you.

I had never before understood why some of the couplings had ridges and
some did not. But also this pipe is only half an inch from the ceiling
so I can't get a regular pipe cutter to roll around it, and would have
to use that saw like a hacksaw blade with a handle at only one end.
I've had trouble doing this before, because the soft copper bends a bit
and is then hard to fit to the coupling. Is there a better way to cut
this pipe, or do I just have to go slowly and ream out the result?

On Mar 16, 7:55*pm, dpb wrote:
Bert Byfield wrote:

...

But my primary leak right now is where a water pipe has been touching
the conduit for the main house power for fifty years or so, and the
contact has caused a pinhole leak, of 5 or 6 gallons a day. I'm
looking at inserting a "universal pipe repair clamp" between the pipe
and the conduit, before I think about replacing sections of pipe.

All you need is a slip over coupling (one w/o the ridge in the middle)
expressly for the purpose.

Cut the pipe at the location of the pinhole, clean the ends (remember to
also ream the inside of the cut to get rid of burs), then slip the
fitting over, flux and solder. * Done.

Then, as somebody else noted, fix the contact point so the two don't
touch in some fashion and it'll probably outlast you.

I'd not worry about the rest until actually had a demonstrable problem.
* Like the above, unless you have something very corrosive in the water
or other problems, likely it will no longer be your problem when it
actually requires replacement.

--

Most of the couplings I see just have a little dimple that keeps the
pipe from sliding through. Needing a repair coupling I have just
hammered the little dimple out. This usually saves me a trip and I
dont have some salesperson asking me what the heck am I talking about.

Jimmie

In article , Speedy Jim wrote:

3/4" pipe has roughly 50% more area than 1/2"

No, it has approximately 125% more area. The exact difference depends on
whether you're talking about type K, L, or M pipe.

One of the women at my church complains there is "never any
hot water". I timed it one night, something like 4 1/2
minutes for the hot water to arrive. I'm wondering if they
used 3/4 copper. I think they have water saver aerators,
which I ought to drill out.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Speedy Jim" wrote in message
...

It will cause a problem if there are long runs on the Hot
side.
3/4" pipe has roughly 50% more area than 1/2", meaning that
50% more volume of water has to be drawn from a distant
faucet
before Hot water arrives. That may be trivial or it may be
a
real pain in the neck.

Stormin Mormon wrote:
One of the women at my church complains there is "never any
hot water". I timed it one night, something like 4 1/2
minutes for the hot water to arrive. I'm wondering if they
used 3/4 copper. I think they have water saver aerators,
which I ought to drill out.


Christopher, you may want to check into putting one of these in at the
farthest away point.

http://www.chilipepperapp.com/

steve

Now, that looks like a useful gadget. I doubt I could "sell"
it to the powers that be. But, it looks useful.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Steve Barker" wrote in
message
...
Stormin Mormon wrote:
One of the women at my church complains there is "never
any
hot water". I timed it one night, something like 4 1/2
minutes for the hot water to arrive. I'm wondering if they
used 3/4 copper. I think they have water saver aerators,
which I ought to drill out.


Christopher, you may want to check into putting one of these
in at the
farthest away point.

http://www.chilipepperapp.com/

steve

wrote:
On Sun, 15 Mar 2009 17:14:08 -0500, Speedy Jim
wrote:

Bert Byfield wrote:
I've got a basement full of old half-inch copper pipe, and some of
it needs to be replaced. I want to do repairs in 3/4" pipe but I'm
wondering if that will cause problems with the water changing pipe
sizes on its way to an outlet. Can I do this?





It will cause a problem if there are long runs on the Hot side.
3/4" pipe has roughly 50% more area than 1/2", meaning that
50% more volume of water has to be drawn from a distant faucet
before Hot water arrives. That may be trivial or it may be a
real pain in the neck.

That's why they sell foam pipe insulation !!!!!!

It would take a lot more than standard pipe insulation to prevent "the wait for
hot water" problem you are responding to.

On Mar 16, 11:28*am, wrote:
On Sun, 15 Mar 2009 17:14:08 -0500, Speedy Jim



wrote:
Bert Byfield wrote:
I've got a basement full of old half-inch copper pipe, and some of it
needs to be replaced. I want to do repairs in 3/4" pipe but I'm
wondering if that will cause problems with the water changing pipe
sizes on its way to an outlet. Can I do this?

It will cause a problem if there are long runs on the Hot side.
3/4" pipe has roughly 50% more area than 1/2", meaning that
50% more volume of water has to be drawn from a distant faucet
before Hot water arrives. *That may be trivial or it may be a
real pain in the neck.

That's why they sell foam pipe insulation !!!!!!

Foam pipe insulation will only cut the hot water wait time by an
insignificant fraction of the current wait time.

Wait time is driven by hot water flow rate to the fixture and volume
of cold water sitting in the hot water piping to the fixture. Volume
of cold water in the hot water piping to the fixture is determined by
run length & pipe size.

Typical hot water pipe insulation will reduce heat loss while the
water is being delivered but it wont keep it hot forever (overnight)

cheers
Bob

wrote:
On Mon, 16 Mar 2009 15:07:29 -0700 (PDT), fftt
wrote:

On Mar 16, 11:28 am, wrote:
On Sun, 15 Mar 2009 17:14:08 -0500, Speedy Jim



wrote:
Bert Byfield wrote:
I've got a basement full of old half-inch copper pipe, and some
of it needs to be replaced. I want to do repairs in 3/4" pipe but
I'm wondering if that will cause problems with the water changing
pipe sizes on its way to an outlet. Can I do this?

It will cause a problem if there are long runs on the Hot side.
3/4" pipe has roughly 50% more area than 1/2", meaning that
50% more volume of water has to be drawn from a distant faucet
before Hot water arrives. That may be trivial or it may be a
real pain in the neck.

That's why they sell foam pipe insulation !!!!!!

Foam pipe insulation will only cut the hot water wait time by an
insignificant fraction of the current wait time.

Wait time is driven by hot water flow rate to the fixture and volume
of cold water sitting in the hot water piping to the fixture.
Volume of cold water in the hot water piping to the fixture is
determined by run length & pipe size.

Typical hot water pipe insulation will reduce heat loss while the
water is being delivered but it wont keep it hot forever (overnight)

cheers
Bob

Guess it depends on the length of the pipes. I have never lived in a
house with hot water pipes that are much longer than 25 feet or so.
Most builders place the water heater in a central location. Of course
these rediculously large homes they build these days are probably
another story.

The only way insulation could solve the problem is if the pipes are VERY short,
and the water heater has no heat trap at all.

Bert Byfield wrote:
I've got a basement full of old half-inch copper pipe, and some of it
needs to be replaced. I want to do repairs in 3/4" pipe but I'm
wondering if that will cause problems with the water changing pipe
sizes on its way to an outlet. Can I do this?





It's not a bad idea to take 3/4 to the last "T" in the system , then
take the last two branchs on in 1/2" . BUT do keep in mind, that on
the hot side, you'll be slowing down the hot getting to the fixture.

You might have to call the public services department in
your town, and get 3/4 inch water instead.

More seriously, it will make little difference, except....
if there is a long run of pipe, or lots of elbows and shut
offs, the 3/4 has lower resistance to flow. And it will take
longer for the hot water to arrive.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Bert Byfield" wrote in message
. 97.131...
I've got a basement full of old half-inch copper pipe, and
some of it
needs to be replaced. I want to do repairs in 3/4" pipe but
I'm
wondering if that will cause problems with the water
changing pipe
sizes on its way to an outlet. Can I do this?