How to Set Air Compressor Pressure

Figure 1: Air Compressor.

Air compressors can be used to power all kinds of pneumatic tools, such as nail guns and other handy tools you might find yourself using to get construction and building projects done more quickly. In order for your air-powered tools to work properly, make sure to set your air compressor’s output pressure to the right PSI range. Don’t be intimidated if you aren’t sure how to do this. It’s really easy to adjust the pressure up or down using your compressor’s pressure regulator knob! Everything else, including the pressure inside the air tank, is automatically regulated by the machine's pressure switch. If you're installing a new switch, adjust the cut-in and cut-out pressures so the compressor turns on and off correctly.

1. Familiarizing Yourself with the Pressure Gauges

1.1 Locate the Air Tank Pressure Gauge Coming off of Your Compressor’s Tank

Look at your air compressor for a gauge attached to a nozzle coming out of the air tank. This is the air tank’s pressure gauge.

This is typically the larger of the 2 gauges on an air compressor:

Figure 2: The larger one of the 2 gauges.

1.2 Identify the Outlet Pressure Gauge Attached to the Compressor’s Airline

Find the airline, which is the hose that connects to your air tools, and look for the gauge near where the hose connects to the tank. This is the compressor’s outlet pressure gauge.

This is usually the smaller of the 2 gauges:

Figure 3: The smaller one of the 2 gauges.

The pressure regulator knob is often right below or beside this gauge where it connects to the airline, though sometimes it is in between the 2 gauges.

1.3 Look at the Air Tank Pressure Gauge to See the Reserve Air Pressure

Check what number the needle on the air tank’s pressure gauge is pointing to. This is how much air pressure, measured in pound-force per square inch (PSI), is available in the tank for you to use. The needle will move down when you use air tools and move back up again when you stop using the air in the tank. The reserve pressure is regulated automatically by a pre-programmed pressure switch. This keeps it within the manufacturer’s accepted range of air pressure PSI.

Your air compressor can’t supply any more air pressure than it has in the tank and it won’t go above the maximum pressure set by the manufacturer’s pressure switch.

1.4 Read the Outlet Pressure Gauge to See the Air Pressure Output

Figure 4: Read the outlet pressure gauge to see the air pressure output.

Take a look at the needle and read the PSI it’s pointing to. This is how much air pressure the compressor will currently supply from the reserve tank to the tool you choose to connect to the airline. The number the needle points to will change when you make adjustments to the pressure. The outlet pressure can never be higher than the tank’s reserve pressure. This is the only pressure that you will need to manually set on your air compressor each time you use a different tool.

2. Using the Right PSI

Check your air tool’s PSI requirements on the tool or in the owner’s manual. Look for a sticker or printed lettering near your tool’s handle or on its underside to see how much PSI of pressure it needs to operate. Refer to the owner’s manual if you can’t find this information on the tool itself.

3. Adjusting the Pressure Regulator

Figure 5: Adjusting the pressure regulator.

3.1 Set up Your Air Compressor with the Tool You Want to Use

Plug your chosen pneumatic tool into the air compressor’s airline hose. Plug your air compressor into a power outlet and turn it on to fill the reserve tank with compressed air.
Turn the pressure regulator knob counterclockwise to decrease the pressure. Look at the needle on the output pressure gauge near the air hose to determine if you need to increase or decrease the output pressure. Twist the pressure regulator knob slowly to the left until the gauge needle points to the correct PSI, if you determine you want to lower the pressure for your tool.

3.2 Turn the Pressure Regulator Knob Counterclockwise to Decrease the Pressure

Look at the needle on the output pressure gauge near the air hose to determine if you need to increase or decrease the output pressure. Twist the pressure regulator knob slowly to the left until the gauge needle points to the correct PSI, if you determine you want to lower the pressure for your tool.

3.3 Rotate the Pressure Regulator Knob Clockwise to Increase the Pressure

Check the output pressure gauge needle to see whether you need to decrease or increase the pressure. Move the pressure regulator knob slowly to the right until the needle on the gauge points to the right PSI, if you decide you must raise the pressure for your tool.

3.4 Test Your Tool and Raise or Lower the Pressure if Needed

Figure 6: Test your tool and raise or lower the pressure if needed.

Try operating your tool on something unimportant to see how it’s working at the recommended PSI, such as a scrap piece of wood if you’re using a nail gun. Turn the pressure up or down by up to 10 PSI at a time if the tool seems like it’s operating weakly or with too much pressure.

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