What Are Fusible Links?

Fusible links are devices in fire suppression systems designed to operate at certain selected temperatures.They release water or fire suppression chemicals when they heat up. They have several designs and models, fusible links can be heat activated at different temperatures.This makes them critical when building fire suppression systems for kitchens and restaurants.

Locations for Fusible Links in Restaurants

Fusible links are heat activated. So, it’s vital to place fusible links in the right places.Links should be placed in areas so that they will be exposed to the heat from a fire should one occur. In the path of exhaust air would be a prime location. However, it’s a requirement that at least one heat detection device is installed above each cooking appliance.It is also a requirement that one is installed in every exhaust duct opening.

How Links Work

Fusible links actually work by cable tension. The links are attached to cables. The tension in the cables is what keeps the system from releasing chemicals that suppress fire. When the links heat up to the designed temperature, the links break apart. This releases the tension in the cable. The release of this tension allows the chemical to flow from the nozzle.

Replacing Links

It’s important to know that these links should be regularly inspected and replaced. If they are not replaced or maintained, they could break at the wrong time. Worse, it could cause the links not to release at the moment a fire occurs. NFPA (National Fire Protection Association) maintains NFPA 96 which covers the installation, testing and maintenance of cooking equipment. In it, they require:

  • Maintenance every 6 months
  • Replacement of links every 6 months
  • A service tag on every link of the installation date and year of manufacture
  • Service tags should have the identity of the service technician
  • Fusible links need to be destroyed when removed


NFPA 96 also requires a maintenance certificate to the sent to local authorities. However, this can be mandated locally.