What kind of filter does a PAPR use?

A welding PAPR blower pulls ambient air through a stack of filter stages before delivering it to the headtop. Kemppi’s PFU 210e operating manual sets out the pattern clearly: a prefilter first, then a particle filter rated P R SL (particulate, “always use a particle filter and a prefilter” for protection against particles), and optionally a combined gas filter — A1B1E1 class on the PFU 210e — fitted behind the particle filter for organic-vapour/inorganic-gas/acid-gas protection when required.

Two variants exist for the prefilter stage on this system: a standard prefilter, or an odour prefilter for nuisance smells — the manual is explicit that the odour prefilter must not be used at the same time as a gas filter. Other manufacturers’ welding PAPRs (3M Adflo, Lincoln Viking PAPR) follow the same general pattern of prefilter → particulate filter → optional gas cartridge, though exact stage names and gas classes vary by brand and headtop. Always match filters to your specific system’s approval label — mixing filter types or brands is against manufacturer instructions and can void the approval.