Article ID: 22-00003
In the oil refinery and petrochemical industry, a containment seal (CS) can be applied to a flashing hydrocarbon pump as a sealing device to prevent environmental pollution. It is extremely difficult to design a CS to ensure the contradictory functions of fluid-tight sealing and sealing surface wear resistance, which are required in both conditions of dry-running in gas and wet-running in liquid. In this study, a new CS design concept “CSAM”(Containment Seal by Additive Manufacturing) for the sealing surface and internal structure of a sealing ring was developed utilizing additive manufacturing. Basically, a lubrication film formed on sealing surfaces of mechanical seals is maintained by opening force (OF) with fluid pressure and closing force (CF) with fluid pressure and spring load. In order to obtain a desired OF, CSAM controls pressure distribution across the sealing surfaces by introducing outside pressure through slots on the sealing surfaces, and an annular cavity is formed within the sealing ring. Based on a series of numerical analyses and static tests, it has been found that the difference between OF and CF can be properly controlled with slot design parameters. The result suggests a possibility of achieving the contradictory functions of sealing and wear resistance in both gas and liquid conditions required of CSs.
