What is the wall thickness of stainless steel welded ventilation pipes?

The wall thickness of stainless steel welded ventilation pipes should be determined according to the caliber size, system pressure and working environment. Generally, it should be implemented according to GB50243, and extra thickening is required under special working conditions. The following are general standards and specifications commonly used in environmental protection engineering for direct selection:

I. Wall thickness of national standard foundation (medium and low pressure ventilation, GB50243)

Duct diameter/length dimension (mm) Standard wall thickness (mm) Applicable to the scene.

≤ 500 0.5 Small-bore general ventilation and clean exhaust

500 ~ 1120 0.75 medium caliber general waste gas and ventilation

1120 ~ 2000 1.0 large-diameter waste gas collection and dust removal

2000 ~ 4000 1.2 Ultra-large caliber and long-distance transportation

> 4000 should be reinforced according to the design to adapt to high pressure/high corrosion conditions.

Second, the common wall thickness of environmental protection engineering (classified by pressure)

Low pressure system (wind pressure < 3 kPa, such as common waste gas collection)

Diameter ≤ 500mm: 0.8 ~ 1.0mm (slightly thicker than the national standard to prevent negative pressure deformation).

Caliber 500 ~ 2000mm: 1.0 ~ 1.2mm.

Medium pressure system (wind pressure 3~10kPa, such as negative pressure dust removal)

Diameter ≤ 500mm: 1.0 ~ 1.2mm.

Caliber 500 ~ 2000mm: 1.2 ~ 1.5mm.

High pressure system (wind pressure > ＞10kPa, such as pneumatic conveying)

Diameter ≤ 500mm: 1.2 ~ 1.5mm.

Caliber 500 ~ 2000mm: 1.5 ~ 2.0mm.

Diameter > 2000mm: 2.0 ~ 3.0mm (need to be thickened or reinforced)

III. Suggestions on Thickening under Special Working Conditions

Highly corrosive medium (acid and alkali fog, chlorine-containing waste gas): wall thickness+0.2~0.5mm (316L material is preferred).

Containing hard dust (ore powder, metal chips): wall thickness+0.5~1.0mm (extra thickening at elbow and reducer)

High temperature flue gas (> 300℃): wall thickness+0.3~0.5mm (according to the national standard foundation wall thickness when selecting 310S material).

Overhead/buried installation: when the overhead span is more than 3m or buried, the wall thickness is+0.2~0.3mm to enhance the rigidity.

Four, commonly used wall thickness specifications

The mainstream thickness of the market: 0.5mm, 0.75mm, 1.0mm, 1.2mm, 1.5mm and 2.0mm；; 1.0mm, 1.2mm and 1.5mm are most commonly used in environmental protection projects, giving consideration to strength and cost.