Question: Have a 3/4" copper to galvanized pipe junction, has a 6" brass
nipple between them. Is this the proper way to do this to prevent
electrolysis?

Other than on a water heater, when would one use an electrically isolated
union? And why?

Al

On Nov 26, 10:06�pm, "Big Al" wrote:
Question: Have a 3/4" copper to galvanized pipe junction, has a 6" brass
nipple between them. Is this the proper way to do this to prevent
electrolysis?

Other than on a water heater, when would one use an electrically isolated
union? And why?

Al

should be dia electric union. the better question why havent ypu
replaced the galvanized ?? PEX is CHEAP and EASY TO WORK WITH!

wrote in message
...
On Nov 26, 10:06?pm, "Big Al" wrote:
Question: Have a 3/4" copper to galvanized pipe junction, has a 6" brass
nipple between them. Is this the proper way to do this to prevent
electrolysis?

Other than on a water heater, when would one use an electrically isolated
union? And why?

Al

should be dia electric union. the better question why havent ypu
replaced the galvanized ?? PEX is CHEAP and EASY TO WORK WITH!

PEX is CHEAP but rodents love it.

"Big Al" wrote in message
...
Question: Have a 3/4" copper to galvanized pipe junction, has a 6" brass
nipple between them. Is this the proper way to do this to prevent
electrolysis?

Other than on a water heater, when would one use an electrically isolated
union? And why?

Al

Brass is neutral metal and will work.

PEX is CHEAP...... that's all that needs to be said.


s



wrote in message
...
On Nov 26, 10:06?pm, "Big Al" wrote:
Question: Have a 3/4" copper to galvanized pipe junction, has a 6" brass
nipple between them. Is this the proper way to do this to prevent
electrolysis?

Other than on a water heater, when would one use an electrically isolated
union? And why?

Al

should be dia electric union. the better question why havent ypu
replaced the galvanized ?? PEX is CHEAP and EASY TO WORK WITH!

On Nov 27, 7:27�am, "Steve Barker DLT"
wrote:
PEX is CHEAP...... �that's all that needs to be said.


individuaL RUN TO EACH OUTLET IS A GREAT SIDE EFFECT TO pex.

plus it routes easily around obstructions, like a beam in the way

heck romex is cheaper than K&T so K&T must be better?

wrote in message

...
On Nov 26, 10:06?pm, "Big Al" wrote:

Question: Have a 3/4" copper to galvanized pipe junction, has a 6" brass
nipple between them. Is this the proper way to do this to prevent
electrolysis?

Other than on a water heater, when would one use an electrically isolated
union? And why?

Al

should be dia electric union. the better question why havent ypu
replaced the galvanized ?? PEX is CHEAP and EASY TO WORK WITH!

On Nov 27, 4:27 am, "Steve Barker DLT"
wrote:
PEX is CHEAP...... that's all that needs to be said.

s


Copper, PEX & PVC all have their place in properly designed &
installed "plumbing" systems.

I have used (& use) all three or a mix of them, depending on the
situation.

All three have their advantages & disadvantages (even copper has some
downside, besides cost).

I always favored copper (before & after the recent price spike) but
once I used PEX, my opinion changed.
I still use copper and often do the copper / PEX hybrid thing.

Don't dismiss PEX, cuz' it's plastic or "cheap"...the system has a lot
of advantages over copper, even soft copper.



cheers
Bob

"BobK207" wrote in message
...

I always favored copper (before & after the recent price spike)

Has anyone noticed copper pipe prices dropping? The metal recyclers are paying a
lot less for copper.

In many, many ways, yes it was.

s

wrote in message
...

heck romex is cheaper than K&T so K&T must be better?

Sac Dave wrote:
"Big Al" wrote in message
...

Question: Have a 3/4" copper to galvanized pipe junction, has a 6" brass
nipple between them. Is this the proper way to do this to prevent
electrolysis?

Other than on a water heater, when would one use an electrically isolated
union? And why?

Al


Brass is neutral metal and will work.




I'd love to hear what makes you think brass is a "neutral metal", Sac Dave.

Have you ever even bothered to look at a galvanic table?

Try spending some time reading articles like this one:

http://tinyurl.com/5sekem

before you hand out totally incorect advice.

*******

Regarding the OP's mention of water heaters, the use of dielectric
unions on them is passe, as stated by Rheem in this bulletin:

http://tinyurl.com/5e56ub

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.98*10^14 fathoms per fortnight.

Jeff Wisnia wrote:
Sac Dave wrote:

"Big Al" wrote in message
...

Question: Have a 3/4" copper to galvanized pipe junction, has a 6"
brass nipple between them. Is this the proper way to do this to
prevent electrolysis?

Other than on a water heater, when would one use an electrically
isolated union? And why?

Al


Brass is neutral metal and will work.



I'd love to hear what makes you think brass is a "neutral metal", Sac Dave.

Have you ever even bothered to look at a galvanic table?

Try spending some time reading articles like this one:

http://tinyurl.com/5sekem

before you hand out totally incorect advice.

*******

Regarding the OP's mention of water heaters, the use of dielectric
unions on them is passe, as stated by Rheem in this bulletin:

http://tinyurl.com/5e56ub

Although I realize that this is not a group organized to further
literacy the first sentence of the Rheem bulletin is not one that
portends great understanding.

The second sentence is more worrisome. "... a shut-off valve in at
least the cold inlet waterline is recommended,..." Where would another
other shut-off valve be placed? In the only other waterline, the hot
water outlet? This is an implied prescription for a bomb, and violates
every plumbing code that I'm familiar with.

The rest of the piece is an attempt at explaining electrochemistry which
is much better done in a plethora of texts.


Jeff

Boden wrote:

-snip-
The second sentence is more worrisome. "... a shut-off valve in at
least the cold inlet waterline is recommended,..." Where would another
other shut-off valve be placed? In the only other waterline, the hot
water outlet? This is an implied prescription for a bomb, and violates
every plumbing code that I'm familiar with.


Since that's how mine is done I'm curious. How is having a shutoff
at the tank any more dangerous than the normal shutoffs at the
faucets?

Can you cite a code that forbids it? Or better yet- an incident where
a [preferably open as that is the normal state] valve on the hot side
caused an explosion?

I agree that it is a minimal advantage, but I'm glad that whoever did
mine, did it this way. When I work on the hot water lines I
shut just them down.

Thanks,
Jim

Boden wrote:

Jeff Wisnia wrote:

Sac Dave wrote:

"Big Al" wrote in message
...

Question: Have a 3/4" copper to galvanized pipe junction, has a 6"
brass nipple between them. Is this the proper way to do this to
prevent electrolysis?

Other than on a water heater, when would one use an electrically
isolated union? And why?

Al


Brass is neutral metal and will work.



I'd love to hear what makes you think brass is a "neutral metal", Sac
Dave.

Have you ever even bothered to look at a galvanic table?

Try spending some time reading articles like this one:

http://tinyurl.com/5sekem

before you hand out totally incorect advice.

*******

Regarding the OP's mention of water heaters, the use of dielectric
unions on them is passe, as stated by Rheem in this bulletin:

http://tinyurl.com/5e56ub

Although I realize that this is not a group organized to further
literacy the first sentence of the Rheem bulletin is not one that
portends great understanding.

The second sentence is more worrisome. "... a shut-off valve in at
least the cold inlet waterline is recommended,..." Where would another
other shut-off valve be placed? In the only other waterline, the hot
water outlet? This is an implied prescription for a bomb, and violates
every plumbing code that I'm familiar with.


I won't quibble with you about plumbing codes, as I'm not a mavin about
them, and it is not unreasonable to expect they'd prohibit hot side
shutoff valves on water heaters.

But how did you come up with "This is an implied prescription for a bomb"?

Can you answer these questions?

Do you know what a T&P valve is and why they're code required on water
heaters?

How is having a closed shut off valve on the hot side of a water heater
significantly different than having all "hot" faucets downstream of the
water heater closed, as they usually are for many hours at a time in an
average household?

Now please defend your "bomb" statement.

*********************************************

BTW, dielectric unions do have their uses in specific situations. One
application I remember is the need to use them in natural gas lines when
they enter a building.

Back in the days when all gas mains buried under streets were iron pipe
(pre-plastic pipe era.) "impressed current cathodic protection systems"
were used to prevent corrosion of those mains.

http://en.wikipedia.org/wiki/Cathodi...sed_current_CP

Dielectric unions were installed ahead of the gas lines where they
entered buildings to avoid having gas appliances (such as water heaters)
from shorting those electrified gas mains to ground.

Jeff
--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.98*10^14 fathoms per fortnight.

The rest of the piece is an attempt at explaining electrochemistry which
is much better done in a plethora of texts.

So??

Jeff
--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.98*10^14 fathoms per fortnight.

Jeff Wisnia posted for all of us...

Sac Dave wrote:

Brass is neutral metal and will work.




I'd love to hear what makes you think brass is a "neutral metal", Sac Dave.

Have you ever even bothered to look at a galvanic table?

Try spending some time reading articles like this one:

http://tinyurl.com/5sekem

before you hand out totally incorect advice.

*******

Regarding the OP's mention of water heaters, the use of dielectric
unions on them is passe, as stated by Rheem in this bulletin:

http://tinyurl.com/5e56ub

Jeff


Muntz metal heh heh heh!
--
Tekkie Don't bother to thank me, I do this as a public service.

On Nov 29, 12:52�pm, wrote:
On Thu, 27 Nov 2008 06:27:19 -0600, "Steve Barker DLT"

wrote:
PEX is CHEAP...... �that's all that needs to be said.

Yep, it cheap, and works great as a temporary garden hose.
When I do plumbing, I want real pipe which will last many decades.
Whether it's copper, brass, or galvanized iron. �I get a laugh with
these trailer homes they use this PEX and since trailers have cheap
skirting, rodents live under them, and feast on PEX and Romex.

My home has galvanized pipe coming in from the main, installed around
1950 and it still works fine. �I replaced all of the hot water pipes
with copper in the 80's and replaced the cold pipes at the fixtures at
the same time because the walls were open. �I can use the galv pipes
to hang stuff, without worrying about some kid ripping the pipes down
and causing a flood.

PEX is about the same thing as plumbing your home with garden hose.
You wont ever find it in my house, as well as the CPVC. �I installed
CPVC to an outdoor spigot in the 90's a few years later it snapped off
at the wall during a cold spell. �GOOD plumbing is METAL. �CHEAP
plumbing is PLASTIC. �

Of course these days, new homes are only built to last 20 years, so
the plastic pipes are fitting.





s

wrote in message
....
On Nov 26, 10:06?pm, "Big Al" wrote:
Question: Have a 3/4" copper to galvanized pipe junction, has a 6" brass
nipple between them. Is this the proper way to do this to prevent
electrolysis?

Other than on a water heater, when would one use an electrically isolated
union? And why?

Al

should be dia electric union. the better question why havent ypu
replaced the galvanized ?? PEX is CHEAP and EASY TO WORK WITH!- Hide quoted text -

- Show quoted text -

copper sometimes gets attacked by water and leaks insde walls etc....
PEX doesnt have that problem and can stand repeated freezing and
thawing