What is a Fusible Link and How is it Fire Safe?

Inflammable or combustible tanks located inside buildings should consist of an automatic closing heat-actuated valve on each outlet connection situated below the liquid level to avoid continued flow of fire proximity to the tank.

The National Fire Protection Association (NFPA) also added to the above precautionary measures by stating that emergency shutoff valves should include the following mandatory means of closing, which states that fusible elements should have a melting point not exceeding 250 degrees F and should be equipped with automatic shutoff through therma (fire) actuation. Manual shutoff should be present both at a remote location and at the installed location.

Furthermore, all storage tanks containing highly inflammable or poisonous materials should be provided with a heat sensitive automatic closure valve on the inlet and outlet of the tank.

To manage fail-safe situations involving the use of combustible compounds, American valve manufacturing companies has created specialized fusible link assemblies made from carbon compounds. Wherever the temperature rises exorbitantly due to a fire, the main valve closes with the rupturing of the fusible link. Therefore, the spread of fire and the threat of explosion are considerably reduced as the flow of the flammable liquids or gases is stopped.

Applications of Fusible Link

A fusible link functions as a fail-safe close valve in a containment system on a gas line, which cuts the flow through the pipeline during a fire. Fusible links offer protection against fire at tank farms, airports, and petroleum plants. Fusible link valve assemblies are found in storage tanks, carrying vessels, or mixing vessels to control the spread of fire by automatic shut-off of flow.

Fire safety protection systems also use fusible link assemblies as a fail-safe open valve. Introducing a fusible link assembly in the fire safety pipeline or fire suppression system can control the spreading of fire by the automatic opening of a valve that would allow the flow of water or fire-suppressing chemicals to douse out the fire, fusible link assemblies can also help in cooling a storage tank.

The innovative design of Valtorc's fusible link assemblies allows the use of a single valve on a pipe instead of two. These assemblies are further subdivided into low torque, mid torque and high torque series. Apart from the other commonly available fusible link assemblies available in the market that  require the placement of a separate manual valve upstream, the Valtorc fusible link assemblies including the low torque and mid-torque are constructed in such a way that a single valve can work as a manually managed unit, even when the fusible link is armed. The option of manual operation is also available in the high torque series, which can be done by just disconnecting the fusible links.  Additionally, the assemblies can be customized to suit the needs of the customer. The valves undergo factory assembly and testing so as to ensure maximum safety and customer satisfaction.

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