Steel Fire‑rated Roller Shutter

Main Structure and Material Technical Requirements

The complete‑set steel fire‑rated roller shutter consists of curtain slats, guide rails, roller‑shaft head box, bottom beam, roller‑shutter motor, electric control box, thermal release device, manual release mechanism and fire‑sealing components. Each steel‑plate thickness is subject to mandatory minimum requirements of national standards, and serves as a key item for on‑site acceptance inspection.

01.Curtain slats:

Nominal thickness of single‑piece slats for Class‑C steel roller shutters ≥1.2 mm; inner and outer steel plates for Class‑A double‑curtain double‑track shutters ≥1.0 mm. Hot‑dip galvanized cold‑rolled steel plate is preferred as substrate. Ordinary black iron sheet shall not be adopted in coastal high‑salt‑fog environments to avoid short‑term corrosion and deformation. The double‑layer cavity is filled with inorganic fire‑resistant rock‑wool core material with density ≥120 kg/m³. Inferior waste filling is forbidden to eliminate fire penetration risks caused by high‑temperature shrinkage. Slats are tightly interlocked and equipped with intumescent fire seal strips to improve smoke‑sealing performance.

02.Guide rails:

Thickness of exposed guide‑rail steel plate ≥3.0 mm. Smoke‑seal strips are embedded in rail grooves to restrict smoke leakage. Guide rails for large‑span openings must be reinforced to prevent curtain slats from offsetting and derailment.

03.Bottom beam:

Steel‑plate thickness ≥1.5 mm with even counterweight. After the shutter fully descends, the gap between bottom beam and floor shall be ≤3 mm. Excessive gap will easily cause smoke penetration and result in failed acceptance.

04.Roller shaft and head box:

Wall thickness of the roller‑shaft steel pipe ≥2.5 mm. The deflection of roller shaft shall not exceed 1/400 of its total length. Intermediate supports shall be added for extra‑wide openings to prevent bending deformation under load.

05.Drive motor and control system:

The roller‑shutter motor and controller shall comply with GB14102.2‑2024 and GB14102.3‑2024. Operating speeds are strictly controlled: electric descending speed 75‑300 mm/s; gravity descending speed under power failure ≤160 mm/s; full closing time of the opening ≤60 s. Exceeding the time limit shall be judged non‑compliant.

Fire‑fighting Linkage Control Logic

Two separate linkage modes are adopted for roller shutters in evacuation passages and fire‑separation zones, which shall not be used interchangeably.

Openings on Evacuation Passages (Two‑stage Descent)

Smoke detector alarm → The shutter descends and stops at an intermediate position 1.8 m ± 20 mm above the floor to reserve space for occupant evacuation; Heat detector alarm within the same fire compartment → The shutter continues descending until full closure to complete fire separation; Remote manual control (Up / Down / Stop) shall be available at the fire‑control room.

Non‑evacuation Passages & Pure Fire‑separation Openings (One‑stage Descent)

Upon detector alarm, the shutter descends directly to the fully‑closed position without the 1.8‑metre intermediate stop.

Emergency Safety Configuration for Power Failure

A 73 °C thermal release device and quick‑release manual mechanism are mandatory standard fittings. When mains power fails, the shutter shall close automatically by its self‑weight, rather than relying solely on motor‑driven operation with electricity. An obstruction‑sensing rebound device shall be fitted at the bottom; the shutter will rise automatically when hitting obstacles during descent to prevent personal crushing injury. All operation signals shall be fed back to the fire alarm control panel.