That’s all folks!

September 9, 2013

Over many years I have provided snippets of information about using air compressors on this blog, and through it, invited people to seek more in-depth information on my air compressor information website.

That website – – has hundreds of pages of information about acquiring, understanding, using and troubleshooting air compressors. That site gets attention and updates almost daily.

So, this is the last post on this blog. It will stay live as long as WP lets it, but there will be no more updates. See for help with your air compressor, won’t you?




Use caution with your air compressor extension cord

June 30, 2013

When using an air compressor that is at a considerable distance from a power source, be sure to use an extension cord that has the capacity to handle the current the tool will draw.

An undersized cord will cause a drop in line voltage, resulting in overheating and loss of power. Often, an undersized cord will cause your compressor motor to go off on thermal overload due to the heat build up.

Find and use a chart (many are available on line) to determine the minimum wire size required in an extension cord. Or, better yet, don’t use an extension cord, but add additional air hose. An air tool will not overheat if there is insufficient air. An electric motor will overheat and possibly stall, creating motor problems.

It is recommended when working with an air compressor outdoors, and you must use an extension cord of the right size, make sure you use an extension cord that is designed for outside use. This is indicated by the letters “WA” on the cord’s jacket.

Before using any extension cord always inspect it first for loose or exposed wires and cut or worn insulation.

What is the piece called that connects to an air compressor to air up a tire?

June 12, 2013

That seems like a straightforward question… ” what is the piece called that connects to an air compressor to air up a tire “.

To get compressed air from your compressor tank to your tire, you will need the following:

Tire chuck to air up a tire

  • an air line with a connector on one end that fits into the discharge coupler on the air compressor
  • at the other end of the air line should be a checked coupler
  • and you need a TIRE CHUCK with a connector on one end, a connector that fits into the checked coupler on the end of the air hose

The tire chuck in the photo does not have the connector. You will need to acquire one of these. It will thread into the fitting shown at the bottom of the tire chuck.

The fixture on the top end of the tire chuck fits over the valve stem in the tire, and when it is pressed over the valve stem, it both opens the valve in the tire, and allows air to flow from the air hose, through the tire chuck, and into the tire.

Why two PRV’s on my compressor?

March 16, 2013

Air compressors with one cylinder typically have one pressure relief valve (PRV).

Air compressors with twin cylinders, those with two pumping cylinders, will typically have two PRV’s. Why?

It is common to have a PRV located near the pressure switch, one that is plumbed into the line coming from the tank to the pressure switch. This PRV oversees the pressure in the tank. Should the compressor not shut off when it is supposed to, the pressure in the tank may rise to catastrophic levels. Long before a tank might burst the PRV will react to the too high pressure, open, and vent air pressure, even while the compressor pump still runs.

On a two cylinder, two stage air compressor, air is compressed from the first cylinder through a line into the second cylinder, before the air is further compressed and driven down into the compressor tank.

Both pump cylinders have intake valves and pressure valves, to help keep the flow of air in a uni-direction, from the outside through the first cylinder, into the second, and into the tank.

Let us surmise for a second that something negative happens to the valve system in the second cylinder, and for some reason air can be pumped into it, but the air cannot be pumped  further along and into the tank.

The first cylinder is pumping away, driving compressed air towards the second cylinder, the second cylinder has become, effectively, a blockade, and since the first cylinder continues to pump, air in the line between the two cylinders can quickly exceed safe levels.

To ensure that an air pressure crisis does not occur if the secondary cylinder fails, there will be a PRV in the line somewhere between the two cylinders that will blow off once the pressure in the line reaches the pressure setting of the relief valve.

A potentially dangerous situation will have been averted.

Test your compressor PRV’s regularly to help ensure that they will work when they are supposed to.

Free Compressed Air?

February 6, 2013

I am a staunch proponent of energy conservation, and compressed air manufacturing and use is a real energy hog.

Would you be interested in some free compressed air?

An enterprising company has developed a valve that will allow some of the compressed air used in cycling an air cylinder to be reused on the return stroke of the cylinder.

If it works, and I have not seen it in operation except for the video below, a significant proportion of the air used to extend or retract and air cylinder can be re-routed from the exhaust port of the power valve into the cylinder port of the retract end of the cylinder, allowing some of the energy in the air that would ordinarily be exhausted to be used again.

Great idea, hope it works. Here is the video. If you have questions about compressed air, visit

Do all air compressors shut off automatically?

January 24, 2013

Good question.

My answer is, typically yes, if they have a functioning compressor pressure switch.

Air compressor pressure switch

In the photo you can see a typical compressor switch.

This is a Lefoo brand. Yours may be like this or it might be a Condor type, or a mini-tube type.

Regardless of the type of switch, they all work in a similar fashion.

The switch will have a low pressure cut in setting and a higher pressure cut out setting.

When the pressure in your compressor tank drops to the cut in pressure setting, the air compressor should start, and pump air into the tank, raising the pressure in the tank.

When the pressure switch senses that the pressure in the tank has reached the cut out pressure level, the pressure switch trips to off, and the compressor stops.

If the pressure in the compressor tank does not get to the cut out pressure setting, the compressor will continue to run. This is not good and should be rectified as soon as possible.

If, on the other hand, the compressor tank pressure reaches the cut out pressure setting of the pressure switch, and the switch does not react by cutting the power to the motor and stopping the compressor, then the pressure in the tank will rise until the pressure relief valve lets go to vent the over pressure. But, the air compressor will continue to run, and this is not good nor is it safe.

Do all air compressors shut off automatically? They should. If yours does not, get it fixed fast as you can.

Do you need a compressed air filter?

January 16, 2013

Do you need a compressed air filter for your home or small workshop air compressor?

Compressed air filter

If you have acquired or purchased a smaller air compressor for your home or garage workshop, chances are it did not come equipped with a compressed air filter. Why?

I suspect that in the drive in the market place to offer the consumer the cheapest possible price for an off-shore manufactured air compressor, it was decided that not including a compressed air filter saved the compressor company a few dollars, and allows them to keep their sell price a little lower.

Should you add a compressed air filter to your home workshop compressor?

Let me answer that question this way.

As soon as an air compressor starts pumping air into the tank or into the mains, it is pumping free water and water vapor too. (See this page for information about why an air compressor pumps water.) That water and water vapor is in the tank, and will migrate out of the compressor tank into your air lines.

How much water? That is determined by a number of factors, all relating to how long the compressor is running, the volume of compressed air being used, the ambient temperature and humidity of the air flowing into the air compressors intake… many factors.

There could be lots of water.

What have you got hanging on the end of your air hose from the compressor? An air tool? A spray paint gun? Just a blow gun If whatever you are blowing air into from the compressor could be negatively affected by water blowing coming from the compressor tank, then do your equipment a favor and add a compressed air filter.

If your air compressor is more than a couple of HP in motor size, rather than use a mini-filter as shown in the photo, consider purchasing a regular sized air filter to help eliminate the air filter as being an impediment to air flow.

And yes, you want to replace the filter element as it clogs up with crud brought down from the compressor by the flowing compressed air.






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