Intro to Millwright Practice Exam

Which two basic types of seals are commonly recognized?

1. Static and Dynamic

2. Soft and Hard

3. Molded and Machined

4. Pressure and Vacuum

The correct answer is: Static and Dynamic

The classification of seals into static and dynamic types is a fundamental concept in the field of mechanical sealing. Static seals are designed to prevent leakage between components that do not have relative motion; they remain stationary while providing a barrier against fluids or gases. This type is often found in applications such as gaskets and O-rings, where they compress to create a tight seal against surfaces. On the other hand, dynamic seals are used in applications where there is relative motion between the sealing surfaces, such as in rotating shafts or reciprocating pistons. Dynamic seals must accommodate movement while still effectively preventing leakage. Examples of dynamic seals include lip seals and mechanical seals, which are specifically designed to withstand wear and maintain integrity during continuous motion. Understanding the distinction between static and dynamic seals is crucial for millwrights as it helps in selecting the appropriate seal type for various machinery and equipment applications, ultimately ensuring reliability and preventing costly leaks or failures.