A compressor apparatus for compression of fluid, comprising: a housing; scroll compressor bodies (110, 112) in the housing including a first scroll body and a second scroll body, the first and second scroll bodies (110, 112) having respective bases (116, 120) and respective scroll ribs (114, 118) that project from the respective bases (116, 120) and which mutually engage, the second scroll body being moveable relative to the first scroll body for compressing fluid through a discharge port; a high pressure chamber in the housing arranged to receive compressed fluid from the scroll compressor bodies (110, 112); and a check valve having a check valve chamber interposed between the high pressure chamber and the discharge port, the check valve including a valve disc and a retainer retaining the valve disc in the valve chamber, the valve disc movable between a valve seat in a closed position and the valve retainer in an open position; characterized in that the valve disc includes a relieved region facing the retainer, and that the valve disc includes an outer annular contact ring located in a contact plane, the contact ring engaging the retainer along the contact plane in the open position and that the valve disc has a first flat state prior to operation of the compressor apparatus and a second state in which an initial operation of the compressor apparatus creates a pressure differential dishing the valve disc from the first state to the second state thereby forming the relieved region, the valve disc having a thickness and being sufficiently soft relative to the pressure differential to facilitate said dishing. a housing; scroll compressor bodies (110, 112) in the housing including a first scroll body and a second scroll body, the first and second scroll bodies (110, 112) having respective bases (116, 120) and respective scroll ribs (114, 118) that project from the respective bases (116, 120) and which mutually engage, the second scroll body being moveable relative to the first scroll body for compressing fluid through a discharge port; a high pressure chamber in the housing arranged to receive compressed fluid from the scroll compressor bodies (110, 112); and a check valve having a check valve chamber interposed between the high pressure chamber and the discharge port, the check valve including a valve disc and a retainer retaining the valve disc in the valve chamber, the valve disc movable between a valve seat in a closed position and the valve retainer in an open position; characterized in that the valve disc includes a relieved region facing the retainer, and that the valve disc includes an outer annular contact ring located in a contact plane, the contact ring engaging the retainer along the contact plane in the open position and that the valve disc has a first flat state prior to operation of the compressor apparatus and a second state in which an initial operation of the compressor apparatus creates a pressure differential dishing the valve disc from the first state to the second state thereby forming the relieved region, the valve disc having a thickness and being sufficiently soft relative to the pressure differential to facilitate said dishing.