A reciprocating surroundings compressor is a positive displacement compressor that uses a crankshaft-driven piston and cylinder to compress the atmosphere. … A two-stage compressor Piston Air Compressor contains an additional step where the surroundings is compressed by a second, smaller piston to a pressure of up to 175 PSI.
Like a small internal combustion engine, a conventional piston compressor has a crankshaft, a connecting rod and piston, a cylinder and a valve head. 
… As the piston moves down, a vacuum is created above it. This enables outside air flow at atmospheric pressure to push open up the inlet valve and fill the area above the piston.
ES 
EN 
PT 
AR 
ID 
KO 
IT 
DE 
ZH 
JA 
RU 
BG 
FR 
ZH-TW