It is not required to have a filter, regulator, or dryer connected to your compressor system for proper operation. However, investing in these added components can improve the quality of the compressed air used for your chosen application and may extend the life of related equipment.
An inline filter is appropriate to protect your piping system from oil mist, dirt, and condensation that may pass from the receiver tank to your end application.
The maximum operating pressure is 175 PSI for Two Stage air compressors. An in-line filter suitable for this range requires a 250 PSI maximum operating pressure)
A regulator may be considered when you desire the pressure of the compressed air delivered to your application to be lower than the rated pressure of your compressor. (For example, if you have a Two Stage compressor that builds 175 PSI and you only need 125 PSI shop air, then installing an external regulator will accomplish this adjustment and prevent unnecessary energy waste.)
If your application requires extremely dry air, an air dryer should be considered to prevent moisture passing downstream, thus protecting your air piping, end application equipment, and surface finishes.