Rectangular duct: The long side size is usually 320mm - 4000mm, designed in sections according to the system pressure rating.
Circular duct: The diameter range corresponds to the long side of the rectangular duct, and the thickness of the spiral duct can be reduced by 10% -15%.
System pressure rating
Long side dimensions (mm)
Thickness (mm)
Description
Low voltage system
≤300
0.5
smoke exhaust system needs to be thickened by 0.2-0.5mm
300-800
0.6
800-1600
0.8-1.0
Medium voltage system
≤630
≥0.6
with an increase of 0.1-0.2mm compared to low voltage
High pressure system
1250
≥1.2
Smoke exhaust system shall be implemented according to high pressure standards
Attention: The thickness of galvanized steel sheet for outdoor pipelines needs to be increased by 0.1-0.2mm to increase the corrosion rate
General requirements: The double-sided galvanizing amount should be ≥275g/m² (zinc layer thickness ≥ 19 μ m), and the clean air duct should be ≥100g/m².
Special environment: It is recommended to use Z600 high zinc coated steel plate (≥600g/m²) or epoxy resin coating in coastal or high humidity areas.
General grade:
DX51D+Z: Suitable for low-voltage systems, with a zinc plating capacity of 275g/m².
DX54D+Z: Recommended smoke control system with better fire resistance performance.
Special Scenario:
Kitchen oil fume exhaust: SS304 stainless steel plate (thickness ≥1.2mm) is recommended.
Connection method: High voltage systems or exhaust pipes must be connected using angle steel flanges.
Anti corrosion treatment: Cold galvanized coating should be sprayed on the weld area, with a coverage rate of ≥95%.
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