The present disclosure describes a system and method for varying pressure from a pressure generator without pressure generator motor speed variations. The system comprises a pressure generator housing, a centrifugal compressor housed within the housing, and at least one impeller blade. The centrifugal compressor is configured to generate a pressurized flow of gas. The pressure generator system includes a pressure adjustment body (e.g., a plate) that is movably attached to and/or within the housing, and an actuator configured to displace the pressure adjustment body with respect to the housing, such that displacement of the pressure adjustment body is configured to regulate pressure of the generated gas flow by varying a gap between the impeller blade and a surface of the pressure adjustment body.