On Sat, 09 Mar 2013 19:54:10 -0800, Gunner
wrote:

On Tue, 05 Mar 2013 16:39:01 -0800, wrote:

On Tue, 05 Mar 2013 18:09:40 -0500, wrote:

On Tue, 05 Mar 2013 17:06:59 -0500, Ned Simmons
wrote:

On Tue, 05 Mar 2013 13:22:02 -0500, wrote:

On Tue, 5 Mar 2013 11:18:31 -0500, "Jim Wilkins"
wrote:

"Joe Gwinn" wrote in message
...
In article
,
Pilgrim
wrote:

Can any one tell me what the difference between rigid conduit and
iron
pipe? inner finish threads on the pipe and in the fittings and any
other
significant differences.

It's not a good idea to use iron water pipe for rigid conduit, even
though the sizes are similar, because water pipe usually has a rough
and sharp longitudinal welded seam that will cut through the wire
insulation during pulling. Conduit, being intended for wire, has a
smooth-walled bore.

Joe Gwinn

Is either better for structural uses?
jsw

Yes and no -depends. Black Iron water/gas pipe today is pretty much
an unknown, quality-wise. Cheap rough Chinese crap in many cases - in
which case Rigid conduit MAY be stronger/more predictable.

ASTM A53 is the standard that covers common steel plumbing pipe in the
US. Even Home Depot and Lowes cite that spec for the black pipe they
sell, so I don't think it's fair to say that the quality of black pipe
is an unknown. It may not be exactly what one might want for a
particular purpose, but it is qualified for its intended use.

The steel dealers around here stock uncoated A53 pipe, which is much
better looking than the black stuff, and preferable if you're welding
or painting it.
Just because it SAYS it meets ASTM A53 spec doesn't necessarily mean
it DOES, you know. A lot of "counterfiet" material around these days.
And the crap will really hit the fan when they prove it was
substandard pipe that caused a gas explosion that levelled a city
block.

One reason given why a pipefitter would not do my external gas barBQ
line in black pipe was he "won't work with that ****" anymore.
I recently bought a black iron nipple to modify into something else.
It was 1/2" pipe, 4 inches long. I parted off the threads on one end
and turned it to .812. I then welded (actually I should say tried)one
end into a mild steel plate. When turning the pipe it looked like
there was porosity in the material but I told myself it must just be
hardness differences in the material that gave it the appearance of
having tiny holes in it. But when welding it the stuff acted like I
was welding without shielding gas. All sorts of bubbles blowing out of
the weld. So I tried running a bead on just the pipe away from the
steel plate and the same thing happened. Running a bead on the steel
plate worked just fine. It was the crappy black iron pipe.
Eric

I do a LOT of air lines in machine shops..and use black pipe
exclusively. For the past 10 or more years Ive been buying my pipe
from a distributor called Fergusens Supply..which has outlets throught
California. Good prices, good service and good pipe.

On a job a couple weeks ago..I ran out of pipe..... and picked up a
piece of 1/2", only 6' long for the same price I get my 20' joints,
from another source. That **** was ****ing nasty to work with. Didnt
thread worth a ****, the threads that were made were broken in places
and it took 2x the effort to spin the threader on it

I dont know where it came from...but I certainly will recognize it
again if I see it. Had a glossy clear coating and white printing on
it. It was Pretty..but that was the only good thing I can think of
saying about it.

Gunner
Couple years ago I bought a IIRC six foot length of 3/4" black pipe
for use as a handrail at the BORG. I wanted it cut and both ct ends
threaded and was informed that there would be no charge for this
service and I must say that I couldn't have done the work any better
myself, this got me a very nice smile from the young lady when I so
informed her.
---

Gerry :-)}
London,Canada