One such critical constituent is gas compression systems. Gas compression systems are very important in oil, gas, and condensate fields. In a lot of oil fields in the North Sea, gas lift using gas compression systems is necessary for oil production. One of the biggest causes of unreliability and inefficiency in gas compression systems is excessive compressor recycling.
Compressor recycling is provided for in centrifugal compressors as mainly a means of protecting the equipment from the surge. As such, the anti-surge control line which launches open the anti-surge control or recycles valve is set in close proximity to the predicted surge region of the compressor map, allowing for an adequate margin of safety. This area is a suboptimal part of the compressor performance map and the centrifugal compressors should not be expected to operate there for prolonged periods under normal conditions.