... 3, Good Balance, Small Vibration 4, Belt Driven Piston Air Compressor Piston Air Compressor Advantages:1, The Cylinder of air compressor are produced by casting way2, Oil saving.3 ... , Adopted import valves, best quality. W3.2/7 Piston Portable Breathing Air Compressor Models:ModelEquippedPower Driven methodRotation speedr/minAir displacementM3/minDischarge PressureMpa LubricationmethodW1.8 ...