It is often desirable to modify process conditions to improve overall plant efficiency or to increase production. However, this often requires rerating an existing compressor.
Before spending a considerable amount of time and effort in redesigning the process, it is advisable to make a preliminary feasibility estimate to determine the rerate capabilities of the existing compressor. This will identify various limitations and help avoid completing a total process redesign only to find out that a compressor cannot meet these new requirements.
The major areas which require evaluation include capacity, pressure, speed, and power. Consider consulting the OEM, and/or a Company specialist before making significant changes to any critical (unspared) centrifugal compressor.