What is the difference between a single and two stage compressor?
Ø The simplest way to explain the difference between a single stage compressor and dual or two stage compressor is the number of times that the air is compressed. In a single stage system the air is compressed once and in a dual stage the air is compressed twice.
Ø In a single stage piston compressor the air is drawn into a cylinder and compressed in a single piston stoke to a pressure of approximately 120 PSI. Then it is send to the storage tank. All rotary compressors are single stage.
Ø In a dual stage compressor the first step is the same except that the air is not directed to the storage tank, the air is sent via an inter cooler tube to a second, smaller high pressure piston and compressed a second time and compressed to a pressure of 175 PSI. Then it is sent through the after cooler to the storage tank.
Ø In a dual stage pump the first stage cylinder is always a larger diameter. Also a dual stage pump will always have an inter cooler tube or finned housing attached to the pump to cool the air before being compressed a second time.