Spares for a powered air respirator welding helmet system: filters, hose, battery, charger, belt, cover lenses and the auto-darkening filter.
Which parts of a powered air welding helmet system wear out and need replacing?
Key maintenance tasks for powered respirators are changing replaceable filters, cleaning, checking straps for damage and checking battery charge and flow rate. Filters load up with fume and cannot be washed or blown clean. Front cover lenses get scratched and pitted by spatter, and batteries lose capacity over time.
Maker manuals also tell you to inspect the breathing hose, face seal, hood and cushion and to replace anything damaged or worn. The helmet shell, auto-darkening filter and blower usually last longer, but they still need checking before use. Your manual lists which parts you can change yourself.
Does a particle filter protect me from welding gases?
No. Particle filters will not protect you from the gases contained in welding fume. They do not trap gases or vapours, and no filter protects in an atmosphere short of oxygen.
Where gases such as ozone are a concern, protection depends on the process, the material and the exposure, and should come from your risk assessment and the maker's instructions. Combined particle and gas filters exist, but only use one your system's maker approves for that unit. Never use a powered unit where the air may lack oxygen unless the maker says it is suitable.
How do I know when the main particle filter needs replacing?
Replaceable filters should be changed when necessary and as the manufacturer instructs, because a clogged filter reduces airflow. Maker manuals tie this to the unit itself: a low airflow alarm that sounds with a fully charged battery, a battery that runs for much less time than before, or a filter that is damaged or wet.
Particle filters are not designed to be washed, tapped clean or blown out with compressed air. The interval depends on how much welding and grinding you do and in what conditions, so follow your manual and risk assessment rather than a fixed number of weeks. Marking the fitting date on the filter is good practice.
How do I check the airflow before I start work?
Check that the fan is providing enough airflow before you use a powered respirator, and never use one that is not providing enough air. Maker manuals add that you should inspect the equipment for damage before every use and test the airflow and alarm as the manual describes.
Fit the filters, spark guard and hose as for normal work, make sure the battery is fully charged, switch on and use the flow indicator or alarm test your manual describes. If flow is too low, check for a loaded filter, a flat battery, a kinked hose, a blocked outlet or a loose connection. If it is still low, do not weld until the unit has been checked.
What should I do if the unit gives a low airflow or low battery alarm?
Treat it as a real warning. Never keep working if the fan stops or the flow rate falls, and leave the work area immediately. Maker manuals say the same for low airflow and low battery alarms, and to leave the contaminated area if the unit stops working for any reason.
Once you are in clean air, look for the usual causes: a loaded filter or pre-filter, a flat battery, a kinked hose, a blocked spark guard or a loose connection. Recharge or replace as needed and repeat the airflow check before going back. If the alarm keeps returning, have the unit examined before it is used again.
How should I look after and charge the battery?
Checking the battery charge is part of routine maintenance for powered respirators, and you should follow the manufacturer's instructions. Charge the battery only as your manual describes: use only the charger the maker supplies for that battery, because a wrong charger can cause a fire, and charge within the temperature range the maker gives. Many makers say to let a hot battery cool before charging.
For long storage, some makers advise keeping the battery part charged and checking it from time to time, and keeping filters in their sealed packs in clean, dry conditions. Much shorter run time is a reason to check the filter first, then replace the battery if it persists. Follow your manual for anything else.