In subsea multiphase pumping systems, the use of a gas-liquid cylindrical cyclone (GLCC) as a separator to recirculate liquid from pump discharge to pump suction, especially during high gas inlet conditions from a multiphase petroleum stream. Further contemplated is protection of the pump from momentary high gas inlet conditions due to an incoming slug flow profile from a petroleum stream, via transforming a naturally varying multiphase petroleum stream into separated phases for measured distribution to the pump suction and ensuring a minimum liquid flow.