The fire performance of a steel fire-rated shutter depends on the quality of its curtain plates and lintel. How are those controlled? RHidoor shares its in-house standards.
Curtain plate requirements:
1. Adjacent interlocked plates must swing freely after linking, with no dropout at ±90° swing. Overlapping smoke-resistant plates must also show no dropout at ±90°.
2. End baffles or anti-shift mechanisms must be fitted firmly; after assembly into a roll, plate shift must not exceed 2 mm.
3. Plates must be straight: straightness no more than 1.5 mm per meter, and no more than 0.12% over the full length.
4. After assembly, no holes or gaps allowed.
5. For smoke-resistant plates, the contact face after the inner and outer nose hooks link must be curved and must contact within a 30° arc.
6. After assembly, no tilt during operation; it must rise and fall parallel. Out-of-flatness no more than 1/300 of the opening height.
Lintel requirements:
1. The lintel structure must effectively block fire spread.
2. A smoke-resistant lintel must carry a smoke device made of non-combustible material to stop smoke leaking out.
3. The smoke device must contact the lintel seal face and curtain surface evenly; contact area no less than 80% of the opening width, and gaps in non-contact areas no more than 2 mm.
4. On-site lintel fitting must be firm; embedded steel parts no more than 600 mm apart.