▎ 摘　　要

NOVELTY - Preparing C-type sealing ring comprises (i) extruding material for the temperature-resistant layer and the material for the elastic layer with an extruder to obtain a strip-shaped embryo, where the cross section of the strip-shaped body includes a core and a ring surrounding the core, and the core is an extruded part of the elastic layer material, the ring portion is an extruded portion of the material for the temperature-resistant layer, (ii) enclosing the strip-shaped embryo body in the mold cavity, overlapping the two ends of the strip-shaped embryo body, and closing the mold, (iii) placing the mold with the strip-shaped embryo body in a drying room for thermal vulcanization, and (iv) stop heating, wait for the temperature of the drying room to drop to ≤50°C, remove the mold, open the mold, and trim the edges to obtain a C-shaped sealing ring. USE - The method is useful for preparing C-shaped sealing ring for channel door of sodium cooled reactor main device i.e. sodium cooled fast neutron reactor. ADVANTAGE - The C-shaped sealing ring: can satisfy structural integrity of structural integrity under the temperature of 531°C; ensures leakage rate is far lower than the technical index of the nuclear power device; has sealing ability of the conventional material cannot be provided; for channel door of sodium-cooled reactor main device is capable of satisfying the service life of the channel door for 40 years, and there is no need to periodically replace the sealing ring in service period.