A reciprocating atmosphere Piston Air Compressor compressor is a positive displacement compressor that uses a crankshaft-driven piston and cylinder to compress the air. … A two-stage compressor contains an additional step where in fact the air is compressed by another, smaller sized piston to a pressure of up to 175 PSI.
Like a small internal combustion engine, a typical piston compressor includes a crankshaft, a connecting rod and piston, a cylinder and a valve head. … As the piston techniques down, a vacuum is created above it. This allows outside air at atmospheric pressure to drive open up the inlet valve and fill the region above the piston.