Multistage compression refers to the compression process completed in more than one stage i.e. a part of compression occurs in one cylinder ( L.P. cylinder) and subsequently compressed air is sent to subsequent cylinders ( H.P. cylinder) for further compression.

Figure shows the schematic of two stage compressor with intercooler between stages.

The total work requirement for running this shall be algebraic summation of work required for low pressure (LP) and high pressure (HP) stages. The size of HP cylinder is smaller than LP cylinder as HP cylinder handles high pressure air having smaller specific volume.

Advantages of multistage compression:

1. Less power required

2. Leakage loss is less

3. Torque is uniform

4. Small size of flywheel required

5. More volumetric efficiency