Journal Artical - BAD IDEA!

[Carl Meyer]

----- Original Message ----- 
From: <JIMRPT@aol.com>
To: <pianotech@ptg.org>
Sent: Tuesday, March 23, 2004 5:38 AM
Subject: Re: Journal Artical - BAD IDEA!


>
> In a message dated 22/03/04 11:48:14 PM, cmpiano@comcast.net writes:
>
> <<  but my caution is that each clamp along the wall
>
> or ceiling will create a loop allowing moisture to collect. >>
>
> This is in regard to 'air hose' runs..............In theory this is
correct
> but as usual theory and reality don't needfully always conincide. :-) A
well
> designed air system has at least two moisture traps....one placed close to
the
> compessor and one placed at the working end termination. These traps will
> sufficiently  remove any moisture which is trapped in the supply line. As
with any
> material used for air line 'air hose' should be installed such that a
drain
> direction is well established...taking any "loops" into account of course.
>
>
> << The rigid
>
> copper tubing should be installed with about 1/4 inch per foot drop.  Each
>
> low spot can be fitted with a drain.  Moisture then will be expelled.  A
>
> compressor running continuously will heat the air and hot air will carry
>
> moisture through the traps.  >>
>
>  Unfortunately copper tubing creates its own moisture/condensation
droplets
> as the air entrained/moving heats up and cools down and thus a copper
system
> requires more in the way of moisture traps than any other piping system
that I
> am aware of. Copper is a terrific conducter of heat/cold and thus is
always
> either heating or cooling the air as it passes through the line. Of course
you
> could insulate the lines but that just raises the cost higher. A well
designed
> copper system is great ..........but the cost of such is the highest of
any of
> the options.


Interesting points and I should let this thread die a natural death in vain,
but I love arguing with you so much that I'm going to take issue with you.
(G)

I was not aware that copper tubing had the ability to create moisture out of
thin air.  If there was no moisture in the air, where did it come from?  As
I said warm air will carry moisture right thru a trap.  Only when the air
has cooled will it give up it's moisture.  If the copper tubing will
condense the moisture, that's a good thing, isn't it?  Insulating the tubing
prevents it from doing its job.  Anyway, most of us have systems that work
well because we don't have  a lot of air requirements.
When I did a job requiring three days of routing out the bottom of a pin
block, my poor compressor got so hot it squirted cold air all over my hand.
That's when I learned that hot air retains moisture and cold air releases
it.  Large commercial air systems use an after cooler to allow the moisture
to condense before the air reaches the system.  Thanks for your input.

Carl Meyer Ptg assoc
Santa Clara, Ca.


> In my opinion the best air system has black pipe for the runs....second
best,
> plain galvanized pipe......third best, copper well insulated.......last
> choice would be air hose.
> That being said my air system is constructed of air hose. :-) I have two
runs
> of aprox 30 feet each with a rise from the compessor of aprox three feet
to a
> system of two regulators and moisture trap....I have a regulator and a
> moisture trap at the working end that is used for spraying. This sytem has
worked f
> aithfully, and without moisture problems, for many years.
>
>  With any system attention paid to draining air tanks and moisture traps
on a
> regular basis is a must.
>
>  PVC......... With PVC there is a possibility, as has been mentioned, of
> "catastrophic failure" and this is true but.........failure of PVC can be
> addressed at its most common cause....that being sunlight caused
brittleness. PVC
> installed should be painted ,completely, to stop this UV caused
deterioration.
> PVC has another very undesirable cahracteristic and that would be the
creation
> of 'static electricity' caused by air movement within the lines. This can
be
> very dangerous. This can be ameliorated by a good grounding system
completely
> sepearate from any electrical circuit grounding system.
>  That being said the PVC air supply system would be my very 'last' choice
and
> only used as a matter of short term neccessity. I know that there are
> advocates of the PVC sytems but due to the brittling and static problems I
choose not
> to use the stuff..............
> My thoughts.
>  JIm Bryant (FL)
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