Abstract: An antisurge apparatus for eliminating surges in compressed air output by a compressor. The compressed air output by the compressor is divided into a first portion of compressed air being supplied to a dump tube for dumping the first portion of compressed air as excess compresssed air to avoid surge and a second portion of compressed air being supplied to apparatus which makes use of the compressed air. The antisurge apparatus includes apparatus for sensing a change in flow of the second portion of compressed air output by the compressor and supplying a flow change signal proportional to flow indicating the amount of the change in flow and apparatus for controlling the amount of the first portion of compressed air being supplied to the dump tube in response to the flow change signal. The antisurge apparatus eliminates compressor surges while minimizing the amount of air dumped as the system or apparatus demand for compressed air increases.