Category Archive: Spiral Torsion Springs

Custom Springs for Fire Dampers

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Custom springs for fire dampers infographic.

Custom Springs for Fire Dampers

Fire dampers need durable, dependable spring components to function effectively. Our springs ensure fire dampers operate efficiently where smoke and fire can rapidly escalate dangers, playing a critical role in saving lives. We offer high-quality, precise spring solutions for duct, HVAC, and automatic fire dampers, meeting the demands of these essential installations.

What Is a Fire Damper?

Ductwork and vents are vital for maintaining health, comfort, and safety by ensuring adequate airflow and temperature control. Unfortunately, they also provide ready conduits for smoke and flame to spread quickly, accessing additional oxygen and fuel during a fire. Fire dampers prevent this spread, they act as valves that automatically or manually close. Typically using a spring-based mechanism, fire dampers halt advancement upon detecting the heat of a fire.

Types of Fire Dampers

Spring-loaded fire dampers offer protection in various ducts and conduits. Here are three common types:

  • Duct Fire Dampers: Installed in duct penetrations they can be manual or dynamic, using a spring mechanism to close and open.
  • HVAC Fire Dampers: Spring-actuated fire dampers in HVAC systems generally close upon detecting a lack of air pressure.
  • Automatic Fire Dampers: These dampers close automatically when environmental conditions reach a set temperature threshold.

At John Evans’ Sons, we produce springs for all these fire damper types.

The Role of Springs in Fire Dampers

Springs ensure fire dampers work properly by providing the power needed to operate the blades or panels inside the dampers. Specifically, these springs:

  • Facilitate simple operation by closing to block flames and smoke when the fusible link breaks, triggering their closure.
  • Allow automatic or manual reopening for regular airflow when safe.

Installing or replacing springs with top-quality, appropriately sized, and styled springs ensures fire damper performance meets and exceeds safety requirements.

Springs Most Commonly Used in Fire Dampers

While traditional helical or round wire springs are used in fire dampers, constant force springs, and spiral torsion springs are most common.

Two Constant Force Springs next to each other.Constant Force Springs

Constant force springs, supply steady and consistent force and are well-suited for the curtain opening and closing actions needed in fire dampers. Commonly used in medical devices, retail displays, and windows, they offer extended, dependable performance. Typically made of stainless steel, their benefits include:

  • Stable, consistent force
  • High power under tight space constraints
  • Smooth, reliable extension and retraction
  • Versatile mounting capabilities with customizable end designs
  • Multiple installation configurations for varying load requirements

The spring’s coil diameter and material thickness determine its life cycle.

Spiral Torsion Spring.Spiral Torsion Springs

Spiral torsion springs provide smooth winding and unwinding, ideal for applications like truck tarps systems, electric motors, medical equipment, and fire dampers. Made from a coiled strip of metal and often of steel for fire dampers, their benefits include:

  • Exerting high rotational torque from small rotations
  • Smooth, powerful action
  • Extremely durable and long-lasting
  • Easy to use and adjust
  • Fit in various settings, especially those with limited space

Picture of John Evans' Sons', Incorporated, facility with logo top left.John Evans’ Sons Fire Damper Spring Design

John Evans’ Sons has specialized in spring innovation and manufacturing since the era of horse-drawn buggies. We produce reliable, powerful springs and spring-based assemblies for industries including medical, aerospace, robotics, and window manufacturing. Our extensive in-house capabilities allow us to produce various spring types and customized solutions to meet diverse needs.

Contact us to learn more about our capabilities or to request a quote for your fire damper and other spring-related applications.