Spare filters, hoses, covers, lenses and comfort parts for a powered air-purifying welding helmet system, and how to match and look after them.
How do I work out which filter my powered helmet unit needs?
Start with the data plate or label on the blower unit and the manual, which name the filter type the unit was approved with. Then compare the markings on the old filter, including its particle class and any part number, with the replacement. For welding fume the filter is normally a particle (P3) type, but a particle filter does not remove gases or vapours.
Do not mix filter types on a unit that takes more than one filter. Fit identical filters, change them together, and never use one past its expiry date. If the old filter has no readable marking, check the manual or ask the maker for the right part before ordering.
When should the main particle filter be changed?
Filters have a limited capacity and can clog, so change them when the maker's instructions say, and sooner if they are damaged, dirty or visibly contaminated, or if the unit can no longer give enough airflow. Welding spatter and heavy fume loading shorten filter life, so how long one lasts depends on the work, not just the calendar.
Do not try to clean a used filter, and do not wait until you can smell or taste fume. A simple habit is to mark the date each filter was fitted. Where the unit has more than one filter, change all of them together. Keep a record of checks and changes as part of your maintenance routine.
How do I check that the unit is giving enough airflow before I start?
Check the airflow every time before you weld, even with new equipment. Most systems use a small airflow indicator tube, which fits the blower outlet or the hose connection. Fit the filters with any transit caps removed, switch the unit on, hold the indicator upright, and compare the reading with the minimum in your manual. If the reading is too low, do not use the unit until it has been serviced.
A low reading is often a sign of a loaded filter, a flat battery or a blocked or kinked hose, so check those first. Many units also have a low-flow alarm, which the manual explains how to test.
How should I look after the battery pack?
Battery condition affects airflow and run time, so treat it as part of the respiratory protection. Before use, inspect the pack and do not use one that is damaged, swollen or leaking. Charge it only as the maker instructs, with the charger intended for that pack, and follow the maker's guidance on charging time.
Store it within the temperature and humidity limits in the manual, away from sunlight and heat sources, because high temperatures reduce capacity. Use only the battery type the unit was approved with. If the unit gives a low-battery or low-airflow warning, or run time falls noticeably, leave the contaminated area and recharge or replace the pack in clean air rather than carry on.
What should I do if the fan stops or the airflow drops while I am welding?
Stop welding and leave the work area straight away, then deal with the problem in clean air. HSE guidance for powered respirators is never to keep working if the fan stops or the flow rate falls, because the helmet then relies on a loose seal that gives little protection.
Common causes are a flat battery, a clogged filter, a blocked or kinked hose, or a loose connection. Check these in a clean area, recharge or replace the battery, change filters as needed, and repeat the airflow check before you return to work. If the fault continues, take the unit out of use until it has been examined by a competent person.
How do I check and look after the breathing hose?
The hose carries all the clean air to the helmet, so check it before each use. Look for cracks, cuts, burn marks, hardened or sticky patches and loose or damaged end fittings, and make sure it is connected properly at both ends. Do not use equipment that is dirty, damaged or incomplete.
Wipe the outside with a mild cleaning solution and let it dry fully before storage, following the maker's cleaning advice. Store the hose without tight kinks or folds. Replace a hose that is damaged rather than taping it, and check that a replacement is the correct type and length for your helmet and blower unit.