ESAB Sentinel A50 Air w/ EPR-X1 PAPR Parts FAQs
Spares and consumables for a powered air-purifying respirator welding helmet system: filters, batteries, chargers, cover lenses, magnifying lenses and comfort items.
What is the difference between the pre-filter, the main particle filter and the spark arrestor?

A blower unit usually has a main particle filter and a pre-filter. The main particle filter is the part that removes welding fume and dust from the air you breathe. The pre-filter is normally a coarser layer that fits over or in front of it and catches larger material, which tends to extend the life of the main filter, especially when grinding.
Some units also have a spark arrestor, a screen that stops hot particles reaching the filter, but not all do, so check your manual. The layout varies, so follow it for the order of the parts and the correct way round. Fit only the parts the maker lists for your blower.
Can I clean or blow out a used PAPR filter and use it again?

No. Used particle filters should not be cleaned or reprocessed. Maker instructions for powered respirators warn that cleaning a filter with compressed air or water can damage it, and the damage may not be visible. A damaged filter can let fume through without you noticing.
If the airflow is low or the alarm sounds, replace the filter rather than trying to clear it. Keep a few spare filters and pre-filters on hand, so you are not tempted to keep using a clogged one. Wipe the outside of the blower housing as the manual describes and keep water out of the unit.
Does a particle filter protect against welding gases such as ozone?

No. The HSE states that particle filters do not protect against gas or vapour, and gas filters do not protect against particles. Welding fume is a particle hazard, so a standard particle filter deals with that, but it is not designed for gases produced by the arc or by solvents and coatings.
Some systems allow an optional gas filter or a carbon-based element for particular conditions. Whether one is suitable depends on your risk assessment, the work, and what the maker approves for your unit. Never fit a filter the maker does not list for the blower, and do not use any filter type in oxygen-deficient air.
Can I use a different battery or charger with my blower unit?

Only use the battery and charger the maker specifies for your unit. A maker's manual for a comparable powered respirator warns that its lithium-ion battery may only be charged with the original charger, because other chargers can cause serious injury. Check that the mains supply matches the charger, and use a charger meant for your battery type.
Charge in a safe, dry location away from the welding area and sparks, within the temperature range in the manual, and not in direct sunlight. If a battery gets abnormally hot, swells or is damaged, stop using it and follow the maker's instructions for disposal.