Check for correct oil level at the ll plug location on the compressor. The oil level is full when oil is at the bottom of the threads in the ll plug hole. Check for oil purging from the air dryer. Refer to the image below as an example.
[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] A portable/towable rotary screw diesel air compressor capable of around 180-260CFM costs approximately $14,000 to $20,000. A heavy duty turbocharged diesel compressor designed for mining, railroad, and heavy-duty construction might cost $25,000 to $30,000 or more.
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