Welding fume extractor: why use it and how to choose it

The new generations of welders, thanks to the training and increase of the culture related to safety in the workplace, are increasingly sensitive to respiratory risk factors. Fortunately for our environment the awareness is spreading that welding operations, if not filtered, generate several health problems related to gases and vapors generated such as:

• Nitrogen oxides: are generated by the combination of nitrogen and oxygen at the temperature of the electric arc.
• Carbon monoxide: is formed by incomplete combustion of organic substances (cellulosic electrodes), carbonates and carbon traces present in steels or filler materials.
• Ozone: it is formed by the effect of UV radiation emitted by the arc at frequencies between 1700 and 2000 °A.
• Pyrolysis products: formed when welding is carried out on pre-painted sheets or in the presence of impurities or still impregnated with solvents used for pickling.
• Possible products: phosgene, aldehydes, phenols, unsaturated hydrocarbons, carbonyl acids, isochromates, hydrocyanic acid.

Welding fume extraction: efficient technical solutions

Close suction is always the best solution and consists in capturing the fumes near the welding. The only products that allow this type of solution are those that use the suction arms, fixed or mounted on board a welding fume extractor. The arms work well even with reduced air flow compared to wall fans or torrini roof fans.

How to properly use a welding fume extractor

• Place the extractor as close as possible to the work area as seen in the video below:

• Work with the hood as close to the weld as possible and not at a distance greater than recommended
• Continuously reposition the hood near the welding point
• Avoid working in air flow to avoid hindering the speed of collection
• Follow the method and frequency of cleaning and disposal of the filters indicated by the manufacturer
• Stop processing in case of malfunction of the device

How to choose a welding fume extractor according to regulations

Due to several poor quality products on the market (because “the important thing was to have it and show it even if it does not work”) portable or trolley welding fume purifiers do not enjoy an excellent reputation with local authorities, which often do not accept them unless they have the following characteristics:

• Certified 99.9% HEPA efficiency filtration to minimize emissions diffused in the work area
• Visual signalling device (yellow indicator) to alert the operator of clogged filters to be cleaned or changed
• Counter on board panel so as to record on the machine register the various filter changes and maintenance carried out
• Low centre of gravity and overall high stability of the extractor to avoid overturning

Often they ask us: does the welding fume extractor really work?

We post below two photos related to the second filter stage and the HEPA filter of a MFU welding fume extractor taken after only 18 hours of operation!! As you can see from the color (which was white) the filter fabrics are impregnated with particles that otherwise would have remained in the working environment and…you breathe.

Secure air – technical Department