NCCER Millwright Practice Exam 2025 – The Comprehensive All-in-One Guide for Exam Success!

The term for seals that are used in areas that are continuously flooded is "open-type seals." These seals are designed to function effectively in environments where they are consistently exposed to liquid, allowing for some degree of lubricant flow while still providing a barrier to prevent contaminants from entering the machinery or system.

Open-type seals typically are used in applications where the environment requires not only sealing against liquid ingress but also where fluid dynamics are acceptable, which is often the case in flooded areas. Their design allows for minimal friction while maintaining effective sealing, thus supporting the operational integrity of the equipment in challenging conditions.

Positive contact seals, dynamic seals, and rotating seals each have their specific applications that are not suited for continuously flooded conditions. Positive contact seals may rely on pressure or direct contact, which may not perform well in constantly wet environments. Dynamic seals are generally better for moving parts where there might be a different type of sealing requirement, and rotating seals are designed for rotating shafts but may not be optimal in a fully submerged setting.