A seal ring construction is provided wherein a seal ring which is formed from a material which is subject to distortion during operation. One end of the ring and portions of the two adjacent sides of the ring which are adjacent the one end of the ring are received in a recess of a stiff shroud assembly. An O-ring recess is formed in each of the sides of the shroud recess which coextend with the two adjacent sides of the ring. Sealing O-rings are positioned in the O-ring recesses and means are formed in the recesses to urge the O-rings into engagement with the sides of the seal ring and into engagement with the inner surface of the shroud recess. The urging means include an inclined surface in each O-ring recess which faces the innermost surface of the shroud recess. In addition, means are provided to take up dimensional differences in the shroud and O-ring components which occur in the manufacturing process.