Air Tools

© Brooke Clarke 2009

To fill the tank on a tennis ball line launcher (used to put up wire amateur radio antennas) compressed air was needed, hence the need for an air compressor.

Rated at 2 HP(peak 1.6 HP running) and 6 Gallons and seem to be on eBay all the time.  The shipper did not properly pack it and the seller sent replacement plastic parts, but that made for a month delay.
For some time I've had an eye out for a vertical tank compressor that might fit into a corner of the garage.  But they are rather pricey for the amount of use it would get and still take up a lot of space.  The beauty of this model is that it's (almost or just?) light enough to pickup can carry.  It's very noisy when running but only runs for a short time before turning off.

Rated at 3.4 SCFM @ 40 PSI and 2.7 SCFM @ 90 PSI
The regulator turns on at 95 PSI and off at 125 PSI.
Weight 51 pounds.

To go with the compressor I got the  Grizzly H5530 5 piece Spray/blow Gun Kit and the H3263 Quick Coupler, 5 piece Set.
The H5530 Includes:

High Pressure Paint Spray Gun

Cleaning Gun

Tire Inflater with Gauge

Blow Gun

Coiled Air hose

It turns out that all the tools come with a nipple fitting so the tool itself has a female 1/4" pipe thread.  Removing the nipple allows the Fig 3 fitting below to be installed.  The nipple has short threads on the tool side and an O-ring.  I'm guessing that it costs less to do it this way than to use a normal pipe thread and apply teflon tape.


In order to install the Coupling (Fig 1) that came with the H3263 set onto the air hose a nipple is needed, so the one removed from the Blow Gun came in handy. 

H3263 Quick Coupler 5 Piece Set

Piece	Where Used
Fig 1	On house with nipple from Blow Gun
Fig 3	On Hose
Fig 3	On Cleaning Gun (spare nipple)
Fig 3	On Blow Gun
Fig 4	On Tire Inflator
	Paint Gun needs fitting

The coupling with a sleeve also is an air valve.  The compressor came with this type of fitting so that when you open the joint almost no air is released.  This type of fitting should be on the supply side of a joint.  When Quick Connect fittings are used it's very easy to change tools without loosing air which would happen if you just used pipe fittings to make the connections.  i.e. every time you opened a pipe fitting all the air in the tank would escape or you would need to close a valve, but even then air will escape from the hose or plumbing.

The fitting at the left traps the valve sprint, washer and valve to the core. The snout of the valve faces to the right and the small bump keeps the spring centered. The core has three balls that hold the plug. When installed the plug opens the valve. The sleeve spring holds the sleeve forward (right). The sleeve is prevented from coming off by the snap ring. Plug has 1/4" NPT as does the inside of the fitting a far left.

Disconnected The vlave is closed (spring not shown for clearer view). Connecting Sleeve pulled back allows ball to rise. Mated The tip of the plug (gray) compresses the washer (green) to make an air seal.  The force from the washer also locks the plug aginst the three ball bearings (red).

	Photo	1/4" NPT Threads	Quick Connect
Air Supply	Fig 1	F	Coupling
	Fig 2	M	Coupling
	Fig 3	M	Plug
	Fig 4	F	Plug
		F	Hose Barb

The compressor came on at night (it's very noisy) calling for powering it down.  Didn't check the pressure often enough to tell how fast the tank emptied itself, but it's now at 0 psi.
Reading the label on the Teflon tape is says "100 psi max" and mentions propane, butane, oil, gasoline, but not air.  Web surfing turns up Loctite 567 and "the" way to seal compressed air lines.  Now trying to locate a local source.

Ideas for leak detection / location.  The stereo ultrasonic bat listening device seems like just the thing.  Liquid soap that forms bubbles is another way.
2 March 2009 - no sound in Ultrasonic Bat listening device.
After about 12 hours the pressure of just the compressor (nothing connected) has dropped from 125 to 114 PSI.
6 March 2009 - 90 PSI.
8 Mar 82 PSI.  The Ultrasonic sensor had a low battery and was not hearing the leak so turned on the compressor bringing it back to 125 PSI, but still did not hear the leak with the new battery.

To extend the distance where compressed air is available an additional hose (Harbor Freight 42184 3/8" x 25' with 1/4" NPT fittings) is being added.  Googling on sealing compressed air fittings turned up a number of related Loctite sealers, but they are not easily available.

 The use of Teflon is questionable.  There are a couple of problems with it.  First, if applied improperly fragments of the tape can enter the air line and might plug up or damage equipment down stream.  Second, Teflon tape may not be rated for the line pressure.  For example using tape rated for 100 PSI when the line is at 125 PSI.

Harbor Freight had Hylomar (97824) at $4 per 35 ml tube so that's what's being used. to attach the fittings to the air hose.  AFAICR Hylomar (Racing Blue) was developed by Rolls Royce for the RB-211 jet engine to form a high pressure seal between two metals with very different expansion coefficients.  It's a plastic that does not set so a joint can be opened then re-closed.  That's very different from Loctite that sets.  It's also rated for hydraulic pressures in the thousands of PSI so can easily seal this air line.

The motivation to get the tank was so that I could use air tools in my office to blow dust out of the computer and in the work room to drive a screwdriver.  A side benefit is the possibility of increasing the compressor tank size from 6 Gal to 17 Gal.  With the 6 Gal tank when you start using any tool the tank empties very quickly and then the compressor starts but can not keep up with most tools or the spray washer.  So this tank triples the tank capacity.  Note that the compressor is rated for some intermittent duty cycle simply adding a larger tank may cause the compressor to run longer than it should which may cause damage.  So I used the red knob on the 11 Gal tank to close the line after it has equalized with the compressor to allow the compressor tank to fill and the motor to stop and cool off.

Uses compressed air as the propellant.

Calls:
1599998 Tube or Pipe Coupling,
2327611 Coupling -  replaces balls
2952482 Coupling with Automatically Activated Cam Sleeve
3028179 Self-Sealing Locking Coupling with Manipulator and Pivoted Latch Means
3628812 Removable Pipe Connector - spring level with notch
3684321 Coupling for Tubes, - Garden Hose type

Calls:
3112767 Quick Connect Coupling, Dec 1963
3423063 Jan 1969
3613726 Oct 1971
3791411 Feb 1974
4060219 Quick disconnect coupler and safety check valve Nov 29, 1977
4437647 Quick connect-disconnect coupling for fluid lines Mar 20, 1984