Selecting Fusible Link Valves
Fusible link valves are a type of valve that is used in shutoff applications as a safety measure. These valves are designed to be used in control systems that deal with flammable, combustible, or toxic materials. The fusible link refers to the part of the valve that is designed to fail. In the event that a certain preset temperature is exceeded, this link releases the tension on a spring, which closes the valve and prevents any process media from flowing past the point in the pipeline where the valve is located.
Fusible link valves mainly consist of a valve connected to a high tension spring. When the valve is opened, the spring is compressed. The link keeps the valve open and the spring tensed. The fusible link is designed to fail at a certain temperature. In case of a fire, the link breaks, releasing the tension on the spring and slamming the valve shut. This keeps any flammable or toxic media contained in the pipeline, reducing the spread of fire and helping prevent unnecessary damage, injury, or loss of life. In terms of safety, this type of valve is an integral part of safety systems and can help a company ensure the least amount of damage or loss in the event of a fire.
Fusible link valves should be used in conjunction with fire-safe valves. These are normally either ball valves or butterfly valves. It is important to make sure the valve used is rated as fire-safe, since it will be used for containment of flammable liquids. These valve assemblies can usually be found on storage tanks, mixing tanks, or transport vessels that require automatic shutoff in the event of a fire.
There are many different applications that benefit from the use of fusible link valves. These applications include petrochemical, pharmaceutical, tank farms, fueling stations, airports, biodiesel, diesel fuels, fire suppression systems, paint applications, and natural gas lines. Any one of these applications requires a fail-closed safety shutoff, which this type of valve can supply. In fact, most insurance companies require the use of these valves before they will provide insurance coverage for the plant or application.
In addition to fail-close applications, fusible link valves can also be used in fire safety protection systems as fail-open valves. This is useful in application where the valve is used to transport water or fire suppression media to the site of a fire when it is necessary. This ensures that the flow of water or fire suppression media is uninterrupted even if the valve fails. These fluids can be used to extinguish a fire or cool a storage tank, among other uses.