RevisionC-Developmentofconceptofcompressorforcommercialvehicle

Clearance Volume: It is a spacing between the top of the piston and the valve’s heads
when the piston is at the end of the delivery stroke. Good quality machines have a clearance
volume of about 6%. But compressors with a clearance of 30-35% are also common. clearance
volume directly affects the efficiency of the compressor. lower the clearance volume higher the
efficiency. Clearance volume is required to meet the below-mentioned points.
• For the mechanical freedom of the moving parts.
• It reduces the noise and vibration
• It also prevents the damage to the moving parts.
Figure 2:8: Terminology Diagram 2
2.3.4 Discharge Pressure, Suction pressure and Compression Ratio
• Discharge Pressure: This is the absolute pressure of the air at an outlet (delivery)
of a compressor.
• Suction Pressure: This is the absolute pressure of the air at an inlet (Suction) to
a compressor.
• Compression Ratio: - This is the ratio of the absolute discharge pressure to the
absolute inlet pressure.
Pad = Absolute Discharge Pressure
Pai = Absolute Inlet Pressure
CR = p ad
P ai
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