Design Terminology for Mechanical End Face Seals

Seal design is still mostly a “state-of-the-art” knowledge. When the application transcends present experience, certain theoretical considerations must be given to predict end results. Often terms used are not clearly defined. Undefined statements for technical discussions are a relative thing and open to interpretation. Therefore, this paper explains the most commonly used terms of the seal designer’s vocabulary. Seal balance and pressure-velocity values are emphasized from a mathematical viewpoint as well as a physical explanation given. Practical examples from laboratory tests and field results are cited.