Where can I find some general guideline for welding ventilation?
Different ventilation strategies may be needed in each case to remove air contaminants from the welder's breathing zone. General guidelines have been published in CSA W117.2 "Safety in Welding, Cutting, and Allied Processes", and ANSI Z49.1 Standard " Safety in Welding and Cutting".
Weld out of the plume. use a tight fitting welding helmet to shield you from the plume.
A well-designed welding helmet can help reduce a welder's exposure to welding fumes by diverting the plume away from the welder's breathing zone.
Local exhaust ventilation (LEV) is always the preferred method of removing welding fumes and gases. It exhausts or removes the toxic gases, fumes, dusts and vapours before they can mix with the room air.
What are some examples of Local Exhaust Ventilation?
Downdraft Bench
A downdraft bench has an open grid work surface. Air is drawn downward through the grid, drawing contaminants into exhaust ducting. Air speed must be great enough to keep contaminants from rising into your breathing zone. If workpieces are too large they may block the ventilation airflow or cause pockets of high velocity air (which could affect shielding gases).
Moveable Hood
Flexible ducting allows the capture hood to be moved where required. Provide an air velocity of at least 100 ft/min (0.5 m/s) across the welding arc. Place the hood as close as practical to the work. The optimal location for the hood is about 1 duct diameter from the arc.
Fume Extraction Welding Guns
The contaminants are removed very close to the source of generation and are drawn through a hose into the exhaust system. They can be very effective on flat and vertical surfaces or in corners and around flanges.
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