Centrifugal versus Reciprocating: General Comparative Advantage

By The Author August 13, 2021

Compressors are machine which is intended to compress a substance in gaseous state and from many types of compressors, centrifugal dan reciprocating type compressor is the most used.

Fig-1 Compressor type chart

The following comparison is in high level comparison without specifying value of operating condition on the comparison.

Advantages of centrifugal type compressor

Reliability/Availability is high, compressor can achieve continuous run typically 3-5 years in clean service without spare.
Machine is relatively small which requires less plot area for installation. It requires smaller foundation support but dynamic load should also be considered.
Installation cost tend to lower due to smaller size and number to be installed. It may impact also to the lower cost.
Maintenance cost is lower.
Compressor has low vibration without pressure pulsation (on the operating region – above surge point). Flow control is continuous over relatively wide capacity range.
Gearbox may not necessary in case Turbine driven which minimizing cost and increase reliability.
There is no oil contamination in to process gas

Disadvantages of centrifugal type compressor

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Generally, has lower efficiency for the same flow rate and pressure ratio
Compressor operation is not efficient below the surge point and therefore recycle is necessary.
Sensitive to changes in gas properties, especially composition/molecular weight/density since the machine has head limitation.
Not suitable for low molecular weight gases, as pressure ratio capability per stage is low it tends to require a large number of machine stages (issue in compressor stability as need more longer shaft)

Advantages of reciprocating type compressor

It is suitable for low-capacity range which below economic range of centrifugal compressors.
Suitable and economic for low molecular weight gas service (very high heads due to low molecular weight)
Compressor is available in very high pressures
Not sensitive to gas composition changes comparing to centrifugal compressors.
Compressor can achieve 0 to 100% stepwise flow variation, via clearance pockets and valve unloaders.
Higher overall efficiency, thus lower discharge temperature.
Flow rate is not sensitive to discharge pressure changes.

Disadvantages of reciprocating type compressor

Compressor is high vibration due to reciprocating forces, it needs large foundation masses and large plot plan
Spare unit are required for continuous services, shorter continuous run primarily due to valve failure
Maintenance costs is higher than centrifugal compressors. More frequent operator inspection is required
Compressor is sensitive to solids carryover (due to use of rubbing parts) and sensitive to liquid carryover (due to destruction of the lubricant film)
There will be oil contaminant in process gas on lubricated type machine