What are the four-hour fusible links commonly referred to as?

The term "four-hour fusible links" refers to a specific type of heat-sensitive device that is commonly used in fire protection systems, particularly in automatic fire doors and smoke compartments. These fusible links are designed to melt at a predetermined temperature, which allows a fire door to close and help contain smoke and flames in the event of a fire, thereby ensuring safety and compliance with fire codes.

The mention of wooden wedges or metal hooks in the context of fusible links is appropriate because these components are often used to secure or release mechanisms in fire door systems. When the fusible link melts due to heat from a fire, it disengages the locking mechanism (often facilitated by these wedges or hooks), allowing the fire door to close effectively.

Understanding the function of fusible links and their association with such hardware components helps clarify their role in fire safety systems. This connection emphasizes the importance of these links in ensuring that fire doors operate correctly in an emergency, contributing to the overall safety and protection strategies within buildings.