Compressors stonewall

A stonewall or choked flow condition occurs when sonic velocity is reached at the exit of a compressor wheel. When this point is reached, flow through the compressor cannot be increased even with further... 

As suction pressure increases or discharge pressure decreases, the compressor head requirement will decrease and the flow rate will increase. A flare valve will avoid stonewalling or overranging driver horsepower. 

Stonewall A term applied to choking at the discharge of a fan or a compressor during operation. Stonewall is evidenced by gas velocities approaching the speed of sound, rapid decreeises in discharge pressure, and noticeable fluctuations in pressure without changes in gas flow rates. 

Excess flow control (stonewall) protection is not needed as long as the compressor is not grossly oversized and the downstream process will provide sufficient backpressure to prevent excess flow. The process fluid is a light hydrocarbon and is never vented directly to atmosphere. 

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