The Utilization of Laser Etched Active Seal Face Surface Features to Maximize Reliability in Ethylene Applications

The requirements for effective sealing of Ethylene in terms of the mechanical seal is a maximization of both seal face stability and interface lubrication. Mechanical seals operating in ethylene and similar light hydrocarbon services will do so with very little hydrodynamic load support due to the low viscosity of the process fluid. It is likely that the seal faces in such applications will operate in a solid to mixed friction regime. In this instance, the face materials are likely to experience higher wear rates in these regions due to increased temperature (from rubbing friction) and potential break down due to significant hydrostatic loading of the faces. The paper will highlight successful seal face component and design implementations utilized to reduce interface frictional heat and leakage, focusing on specific ethylene pump seal installations. Paper will discuss both historical laboratory testing validating performance of active face surface features along with field installations where improvements have been realized by implementing these specific face treatments. In addition, facets of how process seal design strategies coupled with an effective support system can provide improve reliability in these services will be discussed. The aspects discussed should be utilized as a template when evaluating similar problematic applications in the future.