A process control valve (4, 13) with a valve seat assembly, the process control valve comprising: an inlet chamber for containing a high-pressure medium; an outlet chamber for containing a low-pressure medium; a control element arranged between the inlet chamber and the outlet chamber; and a valve seat assembly comprising: a valve seat body having an inner side and an outer side; a groove formed in the valve seat body; and a sealing gasket arranged in the groove, the sealing gasket having an inner side and an outer side; wherein at least a portion of the groove is sunken into the valve seat body at an angle relative to a radius of the valve seat body, and wherein the groove comprises a first part and a second part angled relative to the first part, the first part is inclined downwards toward the inner side of the valve seat body and the second part is oriented parallel to the radius of the valve seat body and the second part is a horizontal groove; wherein the inner side of the sealing gasket is wrapped in the groove, and the shape of the sealing gasket is consistent with the shape of the groove, the sealing gasket being tightly adhered in the groove characterised in that the upper surface of the sealing gasket bears medium pressure. an inlet chamber for containing a high-pressure medium; an outlet chamber for containing a low-pressure medium; a control element arranged between the inlet chamber and the outlet chamber; and a valve seat assembly comprising: a valve seat body having an inner side and an outer side; a groove formed in the valve seat body; and a sealing gasket arranged in the groove, the sealing gasket having an inner side and an outer side; wherein at least a portion of the groove is sunken into the valve seat body at an angle relative to a radius of the valve seat body, and wherein the groove comprises a first part and a second part angled relative to the first part, the first part is inclined downwards toward the inner side of the valve seat body and the second part is oriented parallel to the radius of the valve seat body and the second part is a horizontal groove; wherein the inner side of the sealing gasket is wrapped in the groove, and the shape of the sealing gasket is consistent with the shape of the groove, the sealing gasket being tightly adhered in the groove characterised in that the upper surface of the sealing gasket bears medium pressure. a valve seat body having an inner side and an outer side; a groove formed in the valve seat body; and a sealing gasket arranged in the groove, the sealing gasket having an inner side and an outer side; wherein at least a portion of the groove is sunken into the valve seat body at an angle relative to a radius of the valve seat body, and wherein the groove comprises a first part and a second part angled relative to the first part, the first part is inclined downwards toward the inner side of the valve seat body and the second part is oriented parallel to the radius of the valve seat body and the second part is a horizontal groove; wherein the inner side of the sealing gasket is wrapped in the groove, and the shape of the sealing gasket is consistent with the shape of the groove, the sealing gasket being tightly adhered in the groove characterised in that the upper surface of the sealing gasket bears medium pressure.