A scroll compressor having a scroll wall arrangement with a fixed scroll having fixed scroll walls and an orbiting scroll having orbiting scroll wall, an inlet at a radially outer portion and an outlet at a radially central portion, a first flow path defined by the orbiting and fixed scroll walls and extending from the inlet to the outlet, gas entering through inlet at a pressure and exhausting through outlet at a second pressure higher than the first pressure. Scroll wall arrangement having a second inlet through which gas enters at a third pressure and follows a second fluid path where it is exhausted through the outlet at the second pressure to form two flow paths having respective inlets. The third pressure at which gas enters through inlet is different from the first pressure, and lower than the second pressure.