Lots of folks have compressed air regulator questions. Here are a few that I have received and answered along with a form at the end of this page where you can ask your own air regulator questions.

A visitor asks: I have a Craftsman 3 gal. Air Compressor, 1 hp, Horizontal Tank. Just got this compressor and i just wanted to know how do u adjust the regulator gauge? Ii know i turn the knob but i just don’t know how to adjust it right, do i loosen it or tighten it, to regulate my air, the manual doesn’t tell you how to adjust.


I wrote the eBook The Home Compressor for folks just like you. The manufacturers write manuals, but they seem always to write them from the perspective of someone that already knows all the answers. This eBook is written for folks that don’t already know the answers and want to find out.

Typical air regulator - this one installed with the adjusting knob on the side

Typical air regulator – this one installed with the adjusting knob on the side. The regulator will work in any orientation.

On the top of the regulator knob on my compressor there’s an arrow that shows if you turn the knob to the right a plus (+) happens, and if you turn the knob to the left a minus (-) happens. That means that turning the regulator knob to the right will increase the DOWNSTREAM pressure from the regulator.

I expect that your regulator will work the same way. Your compressor should have two pressure gauges on it. One shows the pressure inside the air tank, and the other, usually mounted on the regulator, shows the pressure setting that you have selected by turning the regulator dial.

If the gauge on the tank says 100 PSI, and the gauge on the regulator says 80 PSI, as long as there is more than 80 PSI air pressure in the tank, the air tools or air using devices downstream from the regulator will get a steady flow of air at 80 PSI.

If you have an air charge in your air tank (the compressor has run until the tank reaches the cut-out air pressure) then watch the gage on the regulator and turn the knob. As long as their is more pressure in the tank than you set on the regulator gage dial, the needle will move as you turn the knob. Then you can see for sure which way to turn the knob on your regulator. Hope this answers your question. Cheers, Bill.

Question: I replaced the regulator reconnected it to the compressor using “plumbers tape” I think that is what it is called but can not get the knob to move either direction. The compressor fills with air but it continues to leak out the end opposite the gauge. which seems to have a plug in it. I have not connected the hose to it yet… maybe that would have helped?


Response: If I am understanding you correctly, you used plumber’s tape is thread sealant? The use of plumber’s tape as a thread sealant isn’t a problem, as long as the tape end isn’t over any hole, causing a blockage or eventually allowing bits of tape to flow down the air line.

You go on to say “the compressor fills with air but it continues to leak out the end opposite the gauge.” I am not entirely sure what you mean by this?

since I cannot see your regulator installation, I don’t know what is on the opposite end of the gauge? Just one quick check. Are you certain that the regulator is installed in the right direction? Regulators normally have an arrow on them showing the flow path of the air from the higher pressure side (tank side) to the application side (hose side). Make sure the regulator is oriented in the air line properly.

As far as adjusting the regulator goes, if you cannot turn the knob, try pushing it down or pulling it up. Some regulators have a mechanism where the handle disengages from the spindle inside. Pushing in, or pulling out, on the regulator handle re-engages the spindle. If that doesn’t help, please make another post, but this time, include photos so I can see what it is you are referring to.

Compressed air regulators questions. Please add your comment here along with photos to help others help you with your compressor and equipment problem!