Looking at a basement rental NG furnace, I noticed that the black steel gas
pipe was joined to the gas valve with a 6" length of 1/2 copper pipe. Is
this legal? Safe? Should not only the black steel, approved for gas pipe be
used?

"Rob" wrote in message
news:OCzFd.99507$KO5.55504@clgrps13...
Looking at a basement rental NG furnace, I noticed that the black steel gas
pipe was joined to the gas valve with a 6" length of 1/2 copper pipe. Is
this legal? Safe? Should not only the black steel, approved for gas pipe be
used?

This is Turtle.

You need to go back to alt.hvac and see a complete run down on this question
that you posted earlier.

TURTLE

NG will eat away at copper. Replace it ASAP.

"Mike" wrote in message
ups.com...
NG will eat away at copper. Replace it ASAP.

What about propane? The propane gas pipe on our boat is copper and about 30
years old.
As part of a refit am replacing gas line anyway. Also take precaution of
always turning off at the propane bottle/tank, a 15 pounder in a separate
ventilated locker at stern of boat, when cooker not in use. However there
will always be gas in the pipe.
Just curious.
Terry.
PS. Is it because of certain impurities (maybe sulphur etc.) in NG that
corrodes copper?

"Terry" wrote in message
. ..

"Mike" wrote in message
ups.com...
NG will eat away at copper. Replace it ASAP.

What about propane? The propane gas pipe on our boat is copper and about 30
years old.
As part of a refit am replacing gas line anyway. Also take precaution of
always turning off at the propane bottle/tank, a 15 pounder in a separate
ventilated locker at stern of boat, when cooker not in use. However there
will always be gas in the pipe.
Just curious.
Terry.
PS. Is it because of certain impurities (maybe sulphur etc.) in NG that
corrodes copper?


This is Turtle.

Propane does not react to copper like natural gas does.

TURTLE

TURTLE wrote:

"Terry" wrote in message
. ..

"Mike" wrote in message
ups.com...
NG will eat away at copper. Replace it ASAP.

What about propane? The propane gas pipe on our boat is copper and about 30
years old.
As part of a refit am replacing gas line anyway. Also take precaution of
always turning off at the propane bottle/tank, a 15 pounder in a separate
ventilated locker at stern of boat, when cooker not in use. However there
will always be gas in the pipe.
Just curious.
Terry.
PS. Is it because of certain impurities (maybe sulphur etc.) in NG that
corrodes copper?


This is Turtle.

Propane does not react to copper like natural gas does.

It's not the "gas" in natural gas that's the problem--it's the sulfur as
Terry suspects (normally in the form of the sulfide (H2S) combined w/
the entrained moisture that's the culprit...

LP's do tend to be "purer" owing to the liquification process that
produces them from NG...

Here's a study from So Cal Ed on corrosion effect of NG on Cu tubing...

http://www.copper.org/applications/f...l%20Report.pdf

I don't know as I agree fully w/ their assessment that the localized
pitting is innocuous as a failure mechanism but I'm not a real
metallurgical type (but I don't get the feeling the folks who did this
study were, either). I do recall a particular product I worked on where
corrosion attack on SS was dramatic although localized. I can envision
similar phenomenon w/ Cu but that's just a "gut feeling", not
engineering data.

"Duane Bozarth" wrote in message
...
TURTLE wrote:

"Terry" wrote in message
. ..

"Mike" wrote in message
ups.com...
NG will eat away at copper. Replace it ASAP.

What about propane? The propane gas pipe on our boat is copper and
about 30
years old.
As part of a refit am replacing gas line anyway. Also take precaution
of
always turning off at the propane bottle/tank, a 15 pounder in a
separate
ventilated locker at stern of boat, when cooker not in use. However
there
will always be gas in the pipe.
Just curious.
Terry.
PS. Is it because of certain impurities (maybe sulphur etc.) in NG that
corrodes copper?


This is Turtle.

Propane does not react to copper like natural gas does.

It's not the "gas" in natural gas that's the problem--it's the sulfur as
Terry suspects (normally in the form of the sulfide (H2S) combined w/
the entrained moisture that's the culprit...

LP's do tend to be "purer" owing to the liquification process that
produces them from NG...

Here's a study from So Cal Ed on corrosion effect of NG on Cu tubing...

http://www.copper.org/applications/f...l%20Report.pdf

I don't know as I agree fully w/ their assessment that the localized
pitting is innocuous as a failure mechanism but I'm not a real
metallurgical type (but I don't get the feeling the folks who did this
study were, either). I do recall a particular product I worked on where
corrosion attack on SS was dramatic although localized. I can envision
similar phenomenon w/ Cu but that's just a "gut feeling", not
engineering data.

Excellent link! Thanks

Rich

"Mike" wrote in message
ups.com...
NG will eat away at copper. Replace it ASAP.


My utility approves K copper for natural gas. It is, as I understand it,
the odor agent that reacts rather then the gas itself. So, it depends on
what the particular utility uses.