UL 555 Fire Dampers
Fire Damper Solutions That Help Limit Fire Spread in HVAC Duct Systems
UL 555 fire dampers are duct-closing devices used to help limit the movement of flames and hot gases between fire compartments through HVAC ductwork.
During a fire event, the damper closes and isolates the duct opening. As a result, it helps limit fire spread through the ventilation system. Motorized, spring-return, fusible-link and automation-controlled configurations can be evaluated for project needs.
UL 555 Design Requirements
Project teams can evaluate suitable fire damper configurations against relevant UL 555 product and installation requirements.
Fire Isolation
The closed damper helps limit the movement of fire and hot gases through duct penetrations.
Automation Compatibility
The damper can work with a fire alarm system, building automation or a mechanical spring-return actuator.
What Are UL 555 Fire Dampers?
UL 555 fire dampers are duct-closing devices for HVAC systems. Engineers install them at fire-rated walls, shafts, floors and compartment penetrations. In a fire event, the damper closes and isolates the duct section.
Industrial plants, commercial buildings, hospitals, data centers, energy facilities and laboratories can use fire dampers to help limit fire spread through ventilation ducts. However, the selected damper, installation detail and rating must match the approved project design.
How UL 555 Fire Dampers Work
Normal Operation
The damper remains open and allows air to pass through the ventilation duct.
Fire Signal
A thermal element, fire alarm or automation signal starts the closing mechanism.
Blade Closure
A spring-return mechanism or motorized system moves the damper blade to the closed position.
Duct Isolation
The closed damper helps limit flame and hot-gas movement through the protected compartment opening.
Key Technical Features
Technical Information
| Item | Description |
|---|---|
| Product name | UL 555 fire damper |
| Reference standard | UL 555 fire damper standard requirements |
| Primary duty | Helps limit fire and hot-gas movement through an HVAC duct line |
| Operating position | Open during normal operation and closed in a fire event |
| Closing method | Thermal element, spring-return mechanism or motorized control |
| Control connection | Fire alarm panel, BMS, automation or manual control option |
| Installation location | Fire-rated walls, shafts, floors or duct penetration points |
| Casing construction | Galvanized steel, stainless steel or sheet metal that matches the project specification |
| Blade construction | Damper blade selected for the required fire-resistance duct-closing application |
| Accessories | Limit switch, actuator, spring-return motor, thermal fuse and connection flange |
Fire Damper Selection Table
| Selection Item | Selection Criterion | Description |
|---|---|---|
| Damper size | W × H or Ø dimension | Defined according to the duct cross-section and project drawing. |
| Installation type | Wall, floor, shaft or duct penetration | Selected according to the fire-compartment penetration detail. |
| Damper type | Static or dynamic | Evaluated according to the fan operating scenario and duct pressure. |
| Closing method | Fusible link, motorized or spring-return | Defined by the fire alarm scenario and automation needs. |
| Accessories | Limit switch, actuator or thermal element | Selected for control, monitoring and building automation integration. |
Materials and Casing Construction
The casing and blade construction of a UL 555 fire damper must suit the required HVAC duct application. Engineers can evaluate galvanized steel, stainless steel or other materials that match the approved project specification.
The damper blade, connection flanges, shaft-and-bearing system, closing mechanism and accessories must match the duct size, installation direction and fire scenario.
Installation Applications
Ordering Information
| Order Parameter | Required Information |
|---|---|
| Model | UL 555 fire damper |
| Size | Width × height or round duct diameter |
| Installation direction | Horizontal, vertical, wall or floor application |
| Control type | Fusible link, motorized, spring-return or automation controlled |
| Accessories | Limit switch, thermal element, actuator, connection flange and control wiring |
Applications
Benefits of Use
Get Information About UL 555 Fire Dampers
The selection of UL 555 fire dampers requires an evaluation of duct size, installation detail, fire compartment, damper type, control scenario, actuator selection, accessory needs and project specification.
Request a technical evaluation for UL 555 fire dampers and HVAC fire safety solutions.
