According to screw compressor manufacturers, treatment is closing the ball valve to verify that the rated pressure can be attained and inspecting the air compressor component to prevent issues with that component constituting the treatment procedure.
[pdf] This test is performed to ensure that there are no leaks in the piping, compressor, or other pressure containing parts of the package. All openings in the completed compressor package are plugged and the unit is pressurized with nitrogen to 350 psig.
[pdf] Diesel air compressors are a reliable and efficient way to get the PSI you need. Pounds per square inch (PSI) and cubic feet per minute (CFM) are two important ratings to consider when you start looki.
[pdf] 
