[michal]

The discharge pressure in centrifugal compressor and centrifugal pumps can be control using discharge throtteling in the same way.?

[mbeychok]

michal:

Yes, the discharge pressure of a centrifugal gas compressor can be controlled by throttling the discharge line.

However, centrifugal gas compressors have a minimum flow rate limit and operating below that minimum flow rate will cause the compressor to "surge" which can seriously damage the compressor. Therefore, all centrifugal compressors should also have a "spillback" line from the compressor discharge to the compressor suction so as to prevent "surging" should the flow be throttled too much. The opening of that spillback line is usually activated by a flow recorder/indicator on the discharge line (upstream of the throttling valve).

The vendor of a centrifugal gas compressor specifies the minimum flow rates (surge points) on the compressor performance curves supplied with the compressor.