To enhance compressor flexibility it is desirable to design into the compressor the capability of operating at other than the original design conditions. If it is desired to provide flexibility to operate at lower suction pressures:
* Add the ability to increase speed or
* Add variable clearance initially, when the suction pressure is high; at lower suction pressure clearance is removed to increase actual throughput.
To provide flexibility for an eventually higher suction temperature:
* Add the ability to increase speed or
* Add variable clearance to reduce capacity initially at low temperature; at high temperature clearance is removed to increase actual throughput.
To provide flexibility for eventually higher discharge pressures:
* Ensure there are enough stages at the outset so that the ratio per stage can increase and still keep within the discharge temperature limits or
* Use variable clearance to adjust ratio per stage.
To provide flexibility for increased throughput:
* Add the ability to increase speed or
* Add variable clearance to reduce capacity initially when the throughput is low; clearance is removed to increase throughput.
