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>While shopping for windows at Home Deopt yesterday I scoped out
>copper pipe fittings for making air lines in the garage of
>the house we're buying. The hard copper pipe and fittings
>doesn't come in anything smaller than 3/4". When you're making
>an air system from copper pipe do you just use 3/4" -> 1/2"
>reducers and 1/2" air couplers?
I have always been able to locate 1/2" fittings. We even plumb our
plant down to 1/2". I don't understand why you can't find them
locally. You can use the same rigid copper fittings as for water
pipes. There is a heavier pipe, type "L", but I have never used it
for air, only baseboard hot water runs that were totally inaccessible,
hopefully it will live longer than I.
>What sort of heat exchanger/water trap should I build?
>Would a simple coil of soft copper tubing with a tee and tap at
>the lowest point to let the collected water flow out of
>the way and get drained be sufficient? Is soft copper tubing
>acceptable for air line use?
Soft copper seems to work just fine for a max of 125-150 psi. I don't
use it but it should work. For moisture traps, try to run your lines
as high as possible at the compressor, then slope it toward your
connector fittings. Use tees for your fittings and drop a 2-3 foot
stub below the fittings. Put a drain valve or pipe plug at the bottom
of the stub. Put a filter/water separator at the tee and put your air
hose connector on the trap.
The moisture will condense in the sloping run and will drain down
into the stub. Some moisture will try to exit the tee and should be
stopped in your filter/trap. Drain the moisture from the traps,
filter and tank before use. If you try to get the water to drain back
to the tank you are fighting the air flow and usually get "slugs" of
water that the filter can't separate.
The sloped run recommendation comes from some publication I read
years ago. It has worked well for me. A true heat exchanger will
work better but be certain the water that you condense can be
separated out. Any low spots will cause problems.
Buy an oil-fog lubricator and you can forget tool problems. A
properly lubed tool will tolerate a lot more moisture. I keep a
separate hose for painting just in case the hose has a little oil left
in it, but have never detected oil in my other hoses. Hope this helps.
>Eric Murray email@example.com firstname.lastname@example.org http://www.lne.com/ericm
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