A reciprocating atmosphere compressor is a positive displacement compressor that runs on the crankshaft-driven Piston Air Compressor piston and cylinder to compress the air. … A two-stage compressor contains an additional step where in fact the surroundings is compressed by a second, smaller piston to a pressure as high as 175 PSI.

Like a small internal combustion engine, a conventional piston compressor includes a crankshaft, a connecting rod and piston, a cylinder and a valve head. … As the piston techniques down, a vacuum is established above it. This enables outside air at atmospheric pressure to drive open the inlet valve and fill up the area above the piston.