What About the Air-Lines?

It's really easy to pick up a low cost airsize is measure on the I.D. A 1/2" air hose will
compressor at the local store anymore. But, howhave a 1/2" I.D., regardless of the O.D. of the line.
do you get the air from the compressor to yourDifferent air line manufacturers will have hose with
application? Folks that are plumbing updifferent wall thickness, so the outer diameters
compressed air lines for their garages orwill vary.To connect PVC or RVC air hose
workshops at home, as well as the professionaltogether, you can use the aforementioned
plant person, have a variety of options with whichcouplers and connectors. Usually the coupler and
to do connect the various air-lines available toconnector has a "barbed" male protrusion, though
them.Usually the air compressor will come with aother styles are certainly available. Make sure the
rudimentary kit which will include a PVC (Polyvinyl"barb" size of the coupler / connector
Chloride) or RVC (Rubber Vinyl Chloride) air hose.corresponds with the internal diameter of your air
If not, these kits are available ashose. A gear clamp (do yourself a favour and
accessories.Rather than having a clutter of airpurchase stainless steel clamps over carbon steel.
hose running across the floor (a trip hazard)A few pennies more, but much longer life) is
consider emulating the factory installation. Haveinstalled on the hose first, and then the barb is
the discharge air line from the compressor run upinserted into the I.D. of the hose. After insertion
to the ceiling in the garage or workshop, and thenof the "barb" the gear clamp is brought up the air
install "drop lines" down to the various locations onhose, over the area where the "barb" is inserted,
the bench where compressed air might beand tightened firmly. Using a small wrench to
used.The discharge from the compressor shouldtighten the clamp is preferable over a slotted
have, at the very least, a compressed air filterscrew-driver which have a tendency to distort
where the air exits the receiver / tank, and thethe nut.There are a variety of other fittings
smaller home-compressors will often have aavailable to join air hose. "Barb" to "barb"
regulator there as well. Compressing air causesconnectors, "barbed" elbows, "barbed" T's, and so
water problems, and you can read more abouton.If you are planning on using a lot of
this in my article in this E-zine entitled "Why doescompressed air, hours worth of tool use at time
water run out my compressed air lines...". Thefor example, your drop legs should have a manual
regulator is necessary too, and you can readvalve at the bottom of them and the supply to
about this in an article titled "Why use ayour tool should be taken about six inches from
compressed air regulator" also on thisthe bottom. The manual valve will allow you to
site.Commercial installations of compressed air willdrain the water that will accumulate there. See for
have a large general purpose compressed air filtermore extensive information on plumbing for
at the compressor discharge, and then a filter,compressed air.As to the smaller air lines
regulator and sometimes an in-line lubricator (oiler)themselves, perhaps running to an air valve,
at each of the points where the compressed airjoining an air valve to a cylinder, or even a small
is to be used, to help deal with compressorair brush or air tool, P.E. (polyethylene) is the air
generated water.The regulator will provide thetube of choice. It is chemically inert, won't rust
ability to control the pressure of the air to thatwith air-borne water, has a variety of fittings
particular application. You might want 90 PSI of airavailable, and is inexpensive.P.E. tube has a variety
to run a grinder at one drop line, but farther alongof fitting styles available.It can be connected with
the bench you might only want 12 PSI for an aircompression-ring (ferrule) type fittings. A nut, and
brush paint set up. Individual regulators give youthen the ring fits over the tube, and once the
this capability. If you are installing a regulator attube is inserted into the fitting, the
each drop location, remove the regulator at thecompression-ring is brought down over the tube
compressor to ensure you have full pressure andand then the nut is tightened onto the thread,
flow to the air main overhead and the dropcompressing the ferrule and created a seal. This
lines.The oiler use is dependant on what it is thattype of fitting is available in many configurations
the compressed air is running.On your workincluding straight fitting, elbow, 'T' and so on.The
bench, at the bottom of each drop line, you caneasiest fitting for plumbing P.E. tube is the "instant"
install a coupler. A coupler is a device into whichvariety. There will be a hole, correctly sized for
you can insert a connector. The coupler will bethe O.D. of the tube, into which the tube, after it
"checked", meaning that compressed air isis cut squarely, can be inserted into the fitting.
trapped at that point until a connector is insertedInside the hole will be an "O" ring type seal, and
into the coupler which opens the "check" andthen a collar of small metal fingers through which
allows air to flow.Compressed air can then bethe tube passes. When the air is turned on, the
supplied to the air tool or whatever you wish toP.E. tube swells a bit, and these "fingers" dig into
drive with compressed air via an air-line extensionthe surface of the tube, holding it in. The "O" ring
cord. You can purchase ready made or you canprevents escape of the compressed air. There will
make your own. They are lengths of air hose orbe a small ring on the exterior of the fitting which,
tube with a connector at one end and a couplerwhen depressed, will "bend" the fingers out of the
at the other. The air tool will have a connector inway, allowing the tube to be removed from the
it's air port. When ready to supply compressed airfitting when necessary. This should only take place
to your tool, you simply insert your air-lineif the air is off."Instant" type fittings may not
extension cord connector into the drop linework on soft air-line tube, such as polyurethane.
coupler, and the other end, which will be a coupler,Copper tube may present a problem too, as the
has the air tool connector inserted into"fingers" cannot easily grab the smooth surface of
it.Connectors and couplers are not all the same.the tube.There are some manufacturers that
Different manufacturers have differing styles andoffer a line of miniature barbed fittings for tube. If
they are not usually interchangeable. When youyou are installing many fittings in your application,
first start purchasing couplers and connectors forthey may offer a lower cost solution. The
your air line, make a note of the brand firstdownside is that they significantly reduce the air
purchased, and purchase the same brand as yourflow through the smaller I.D. plastic tube.For a
needs continue.I remember the differencegood selection of air line couplers, connectors,
between a coupler and a connector by making ahose, tube and fittings, consider locating and
mental image of a "cup" into which I insert thevisiting your local industrial supplier of fluid power
connector. The "cup" is the coupler.If it were meor compressed air components, rather than your
installing an "air main" and drop legs down to mylocal hardware or department store. Not only will
workbench in my garage, I would use solderedthe industrial supplier likely have everything you
copper pipe. Copper pipe won't rust, and there areneed in one location, undoubtedly, they too will
more than sufficient adapters available to converthave the expertise to provide the advice that will
from the soldered (sweated) copper to anot necessarily be available at the other retail
thread.If opting for an overhead main, know thatoutlets.If you have questions, please don't hesitate
the longer the supply line to the application, theto visit my site and send me an email through the
more pressure loss there will be. Each elbow andcontact page there.Bill Wade's experience in
every turn creates a loss in available pressure atcompressed air and other industries spans
your application, so make the air main as large asdecades; from field sales positions through to the
practical. How big? Why not 3"' copper pipe at thecorporate presidential office. His sales agency
ceiling and 3/4" copper drop lines for the homerepresents a select group of industrial firms. Mr.
workshop?Remember that PVC or RVC air hose