Oval sealing rings made of 98% pure graphite, manufactured from heat-resistant fabrics treated with elastomers that allow use at high temperatures while maintaining optimum springback. Thanks to the composition of the inner core, which is reinforced in warp and weft with brass threads, high resistance to cutting, tensile strength, pressure and particularly severe conditions is achieved. The graphite treatment on the finished piece avoids the use of release agents, grease, or other chemical substances during maintenance that would damage its technical characteristics.