Bohler Evolution Vision 65FM Air Parts FAQs
Answers on choosing, fitting and looking after the filters, lenses, comfort parts, battery and blower parts for a powered air welding helmet.
What does the filter cover do and how often should it be changed?
The filter cover holds a coarse pre-filter and usually acts as a first barrier against sparks and larger particles, which helps protect the main particle filter behind it. It takes the heaviest wear, so it is normally changed far more often than the main filter.
How often depends on the maker, the process, the material and how dusty the work area is. Some makers suggest changing a pre-filter once or twice a week in regular use, but follow your manual. Change it sooner if it is visibly dirty, clogged, damaged or burnt, and never run the blower without the covers and filters fitted.
How do I know the main particle filter needs replacing?
Common signs are a low-airflow alarm, a filter indicator showing it is spent, a much shorter battery run time than before, or visible damage or heavy contamination. A harder-to-breathe or weaker flow of air is also a warning.
HSE guidance says filters should be changed when damaged or visibly contaminated, and fan-assisted units should follow the manufacturer's instructions for changing them. Some makers also set a minimum change interval even if no alarm has sounded, so check your manual. If an alarm sounds, leave the work area and fix the cause before welding again.
What should I check on the blower and battery before each shift?
Check that the battery is fully charged, the correct filters and covers are fitted, hoses and seals are undamaged and the unit starts normally. Then check the airflow in the way your manual describes, using the maker's flow-check method or device, and make sure any alarm is working.
HSE guidance on powered respirators lists changing filters, cleaning, checking straps, and checking battery charge and flow rate among the key maintenance tasks, with examination and testing done to the maker's schedule by a competent person. If airflow is below the maker's stated minimum, do not weld until it is corrected.
When is a blower motor unit the problem rather than the filter?
A blower motor draws air through the filter and passes it to the helmet. If the flow is low even with a fresh filter, a fully charged battery and a clear, undamaged hose, the fault may lie with the motor, the seals or the electronics.
Before you suspect the motor, rule out the simple causes: a blocked cover, a kinked or loose hose, a missing seal, a tired battery. Anything beyond cleaning and part swaps should be done by a competent person following the manufacturer's instructions, because HSE advises that more intricate repairs are not a job for the wearer. Test the airflow again after any repair.