Spares for a powered air-purifying welding helmet system: filters, pre-filters, batteries, lenses, hose covers and comfort items, and how to pick the right ones.
How do I make sure a spare part fits my powered respirator and helmet?
Start with the data plate or label on the blower unit and the helmet, then the manual, which lists the parts that belong to that system. Compare the part number or marking on the old part with the new one, and check that the blower, filter, hose and helmet are meant to be used together. Makers generally state that only original or specified parts should be used with their respirators, because other parts may mean the protection level no longer meets the stated standard and may void the warranty.
If the markings are worn away or you are unsure, check with the supplier before buying rather than guessing from a photo.
When should I replace the main particle filter on a powered respirator?
There is usually no single fixed time. Makers normally say to replace it when it is clogged, which shows up as the low-airflow alarm sounding, a filter indicator on the blower, or a battery that runs for a much shorter time than before. Some makers also set a maximum working time for hygiene reasons, so check your manual.
A particle filter must never be cleaned, blown out or washed to extend its life, and the new one should be unused, undamaged and within its expiry date. Fit it exactly as the manual shows, with any pre-filter or spark guard in place.
How do I check the airflow and what does the alarm mean?
Check the airflow before every use, using the method in your manual. This is usually a flow indicator or meter supplied for the purpose, or a battery and flow status display on the blower, and the manual will also describe how to test the low-flow alarm. If the airflow is below the stated minimum, or the alarm does not work as described, do not use the unit until it has been put right.
An alarm while working means the unit can no longer hold the set airflow, often because of a clogged filter or a low battery. Leave the contaminated area at once, then change the filter or recharge or replace the battery in clean air. If the blower stops, do not carry on working: protection is reduced and carbon dioxide can build up inside the helmet.
What does a P3 particle filter protect against, and what does it not?
A P3 filter is a high-efficiency particle filter, which is the type normally used to deal with welding fume. It removes solid and liquid particles from the air passing through the blower.
It does not remove gases or vapours, such as those from solvents, degreasers or certain coatings. A particle filter must not be relied on for gas hazards, and if both particles and gas are present you need a suitable combined filter and a risk assessment. Check what contaminants are in your work area and the filter markings in the manual before choosing.
What is a pre-filter for, and when should I change it?
A pre-filter fits over or ahead of the main filter and collects the larger particles, so the main filter clogs more slowly. Makers state that it prolongs the life of the main filter, and a clogged filter also shortens battery run time because the blower has to work harder.
Change it when it looks dirty, discoloured or loaded with dust, or if it is damaged. There is normally no fixed number of hours, so use the manual and your own experience of how much dust and fume your work creates. Always refit any spark guard the system requires, because sparks can damage the filter.
How should I look after the battery and charger?
Use only the charger and battery intended for your system and follow the charging instructions in the manual. Charge in a dry, ventilated place away from anything that could burn, and do not cover the charger. Fire services advise not leaving lithium-ion batteries charging unattended, so disconnect the battery once it is charged unless the maker states that the charger is designed to stay connected.
Do not charge or keep using a battery that is damaged, swollen, leaking, very hot or smelling odd. Batteries slowly lose charge in storage, so charge before use after a long break. A battery that no longer holds a charge, or gives short run time even with a clean filter, should be replaced.