Types of Fusible Links and Their Applications in Fire Equipment

Fire safety systems serve as the last line of defense when fires threaten buildings. Fusible links are small components within these systems ready to activate at the first sign of dangerous heat. These devices serve as thermal triggers in fire doors, dampers and suppression systems to contain fires before they can spread.

Learn more about these components and find the right fusible link in our guide below.

How Does a Fusible Link Work?

A fusible link consists of two metal plates joined by a specialized eutectic alloy designed to melt at a precise temperature threshold. When ambient temperature reaches this predetermined point, the alloy melts, allowing the connected pieces to separate. As these fire safety components release, they cause a mechanical reaction, which could be closing a fire door, dropping a damper in the ventilation system or activating a suppression system.

Unlike electronic sensors that can malfunction or lose power during emergencies, fusible links operate on basic physical principles. Fusible link temperature ratings range from 135 to 500 degrees Fahrenheit, allowing precise calibration based on location and application requirements.

Fire safety systems rely on active and passive components working together to protect buildings and occupants. While sprinklers and alarms are critical parts of these systems, fusible links operate behind the scenes as critical failsafe devices that activate without power or human intervention.

Applications of Fusible Links in Fire Equipment

Fusible links are critical for numerous fire protection applications, providing reliable thermal activation without requiring power or electronic controls. Their simplicity and dependability make them ideal for various safety systems throughout commercial, industrial and residential properties.

• Fire sprinkler systems: When choosing a fusible link for a fire sprinkler, note that these parts serve as heat-responsive triggers and should be selected based on the normal temperature in the setting. Dry pipe systems help control water access to prevent freezing while enabling rapid response during fire events. The precise temperature rating selection ensures activation only occurs during genuine fire conditions.
• Restaurant kitchen equipment: The metal link-style is generally the best type of fusible link for kitchen fire suppression, providing reliable protection in environments where fires can spread rapidly among flammable cooking oils.
• Fire dampers: HVAC systems allow fire and smoke to travel throughout buildings. Fusible links installed within fire dampers melt during fire conditions, releasing spring-loaded or gravity-operated blades that seal off ductwork. This compartmentalization prevents smoke spread and helps maintain the integrity of fire-rated walls and floors.
• Fire doors: Self-closing fire doors often incorporate fusible links as fail-safe release mechanisms. During normal operation, these links hold doors open for convenience, but immediately release when exposed to fire temperatures, allowing doors to close automatically and maintain fire barriers between building sections. This passive protection requires no human intervention to contain the fire spread.
• Industrial fire protection: Manufacturing facilities with high-temperature processes require specialized fusible links that will not activate during normal operations but respond quickly to actual fire conditions. These links usually protect valuable equipment and hazardous material storage areas with customized suppression systems.
• Fire roof vents: Smoke and heat vents on commercial building roofs use fusible links to automatically open during fires, releasing superheated gases and smoke that would otherwise ignite the fire and impede firefighting efforts. This venting helps reduce internal temperatures and improves visibility for evacuating occupants and responding to fire crews.

What Is the Lifespan of a Fusible Link?

Generally, fusible links should be replaced every few years. Many factors affect the lifespan of a fusible link, including its environment. Following a specified inspection schedule can help you maintain your overall fire safety system. For example, fire dampers must be inspected every four years following their first-year inspection.

NFPA codes and local fire regulations mandate specific requirements for fusible link selection, installation and maintenance. Property owners must adhere to inspection schedules varying by application and insurance evaluations. Proper documentation of these inspections is essential during safety audits, so be sure to maintain a clear inspection record.

Types of Globe Fusible Links Offered by National Fire Supply

National Fire Supply offers numerous types of Globe Technologies fusible links for varying applications in fire equipment. Our inventory provides property owners with a reliable way to find the right components, whether for commercial kitchens, industrial facilities or standard building safety systems. This variety allows safety professionals to customize protection based on environmental factors, potential heat sources, and compliance requirements.

Each Globe fusible link is manufactured using high-grade eutectic alloys under ISO 9001:2015 specifications.

Based on Activation Temperature

Globe fusible links are available with many activation temperatures, with fusible link temperature ratings typically ranging from 135 to 500 degrees Fahrenheit. This temperature diversity serves a key purpose — environments with different ambient temperatures and heat sources require precisely calibrated activation points.

• 165-degree Fahrenheit links often serve standard applications in climate-controlled buildings.
• 212-degree Fahrenheit fusible links protect areas with higher temperatures, such as boiler rooms or industrial kitchens.
• 280-degree, 360-degree, 450-degree and 500-degree Fahrenheit fusible links prevent false activations where processes generate significant ambient heat.

Based on Fusible Link Style or Type

Globe fusible links come in several styles, each engineered for specific applications.

• Metal link-style fusible links are particularly popular for range hood protection systems in commercial kitchens, where rapid activation is essential to contain grease fires before they can spread to surrounding areas.
• K-style links typically feature slightly lower activation times, making them suitable for applications where measured response prevents unnecessary triggering.
• B-style links are designed for high-load applications where strength and reliability are top considerations.
• A-style links provide versatility for standard fire protection systems in commercial buildings.
• Test links offer a special advantage for system testing and verification, allowing fire safety professionals to easily confirm proper mechanical operation without activating the entire system.

Globe’s 360-degree Fahrenheit fusible links provide omnidirectional heat sensing, making them ideal for fire dampers and ventilation systems where heat can approach multiple angles. When selecting the appropriate style, property owners should consider the activation temperature, mechanical properties and connection methods that seamlessly integrate with existing fire protection systems.

Based on Material

The materials used in Globe fusible links significantly impact their performance and longevity in different environments. Bronze components offer excellent thermal conductivity and moderate corrosion resistance, making them suitable for environments with higher humidity or mild chemical exposure. For harsh industrial environments with chemical vapors or extreme humidity, stainless steel components deliver superior corrosion resistance and durability.

National Fire Supply’s fusible link range covers all these material options, allowing property owners to select fusible links that maintain their integrity and functionality throughout their service life, even in demanding environments like commercial kitchens, manufacturing facilities or chemical storage areas.

Where to Buy Fusible Links for Industrial Fire Systems

Fusible links represent the critical junction between detection and action in countless fire protection systems. From restaurant kitchens to industrial facilities, these precision-engineered components provide reliable protection without requiring power or complex electronics. Available in multiple temperature ratings, styles and materials, Globe fusible links offer property owners customized protection tailored to their specific environments and safety requirements.

National Fire Supply offers the industry’s widest selection of Globe fusible links to meet your fusible link requirements. Globe is a premier fusible link manufacturer known for uncompromising quality and reliability. These American-made devices provide specialized fire protection in commercial buildings when seconds matter most.

Browse our extensive selection of Globe fusible links today to make sure your fire safety systems meet the highest standard of protection and compliance.