The mechanical seal is the main sealing element of a machine or equipment as it prevents unwanted leaks from occurring and causes accidents and damage. The static and dynamic sealing faces are responsible for performing the primary sealing, while O rings perform the secondary seal, preventing fluid from escaping to an external environment or external impurities from entering the interior of the seal. It is of fundamental importance for the user who wants to perform a seal to study the possible solutions to their problem, and, after applying it, to track their performance to see if the solution can be optimized. This paper presents the concept of mechanical seals, explaining its function, design, operating principles, applications, among other relevant subjects to the understanding of this sealing element. Throughout the work, a mathematical analysis of the seal performance was performed, considering factors such as heat exchange, leakage and lubrication. Finally, a finite element analysis was performed to evaluate or influence temperature and pressure on a mechanical seal performance.