loading creates a venturi effect that compresses gas bubbles within the fluid stream and prevents damage to the downstream compressor stage 130 when the fluid discharged from the diffuser 134 includes a low liquid fraction the force exerted by the spring 139 overcomes the hydraulic force exerted on the variable metering member 138 and the variable metering member 138 returns to a position adjacent the diffuser 134 as shown in fig7 b to permit the high volume flow of high gas fraction fluid through the nozzle stage 128 turning to fig8 shown therein is a perspective view of the gas compressor turbine 140 of the gas compressor stage 130 the gas compression turbine 140 may include a series of upstream compressor vanes 160 a hub 162 a series of ports 164 passing from the upstream side of the hub 162 to the downstream side of the hub 162 and a series of downstream compressor vanes 166 the upstream compressor vanes 160 are configured to induce the flow of fluid through the gas compressor stage 130 fluid passes through the hub 162 through the ports 164 and into the downstream compressor vanes 166 the downstream compressor vanes 166 are designed to increase the pressure.