Sealing rings As delivered, or unassembled, the sealing rings haver the “actual dimensions” as stated in the table. To ensure a firm seating and reliable sealing, an installation space must be provided in the component as shown in the diagram. This ensures that when the sealing ring is installed, it will be subject to the necessary pressure without excess load. All surfaces which are in contact with the sealing ring should have a minimum surface quality of Ra 0.8 μm.