When you are planning on using your air compressor with a pneumatic tool, you will need to adjust your air compressor pressure to meet the specifications of your specific attachment. After you have hooked up your air compressor tool, you can adjust the pressure by carefully turning the adjustment knob. The pressure of the air compressor can be adjusted when the compressor is turned on and running. For more information about air compressors, be sure to contact a company offering air compressors for sale in San Jose. To view the process of adjusting your air compressor pressure, watch this video from expertvillage.